diff --git a/crates/algo/src/blur.rs b/crates/algo/src/blur.rs
index 9d2fe45001..2ca3bcc88b 100644
--- a/crates/algo/src/blur.rs
+++ b/crates/algo/src/blur.rs
@@ -348,19 +348,83 @@ fn average_samples(src: &Image, out: Rect, ctx: &Ctx, mut offsets: impl FnMut(f3
     res
 }
 
-pub(crate) fn motion(src: &Image, out: Rect, ctx: &Ctx, angle: f32, distance: f32) -> Vec<f32> {
+/// Sample offsets of a motion blur of `distance` at `angle`, relative to the pixel centre.
+fn motion_offsets(angle: f32, distance: f32) -> Vec<(f32, f32)> {
     let d = distance.abs();
-    if d < 0.5 {
-        return src.crop(out);
-    }
     let (s, c) = angle.to_radians().sin_cos();
     let steps = d.ceil() as i32;
-    average_samples(src, out, ctx, |x, y, pts| {
-        for i in 0..=steps {
+    (0..=steps)
+        .map(|i| {
             let t = i as f32 / steps as f32 - 0.5;
-            pts.push((x + c * d * t, y - s * d * t));
+            (c * d * t, -s * d * t)
+        })
+        .collect()
+}
+
+/// Motion blur: the mean of bilinear samples along a line centred on the pixel. The offsets are the
+/// same for every pixel, so their bilinear taps are merged once into a fixed kernel, which is
+/// applied tap by tap to whole rows of a premultiplied window (the same premultiplied mean the
+/// per-sample loop takes, summed in another order).
+pub(crate) fn motion(src: &Image, out: Rect, ctx: &Ctx, angle: f32, distance: f32) -> Vec<f32> {
+    if distance.abs() < 0.5 {
+        return src.crop(out);
+    }
+    let offs = motion_offsets(angle, distance);
+    let k = 1.0 / offs.len() as f32;
+    // Merged taps (dx, dy, weight), in the order first seen.
+    let mut taps: Vec<(i32, i32, f32)> = Vec::new();
+    let mut slot = std::collections::HashMap::new();
+    for &(ox, oy) in &offs {
+        let (x0, y0) = (ox.floor(), oy.floor());
+        let (ax, ay) = (ox - x0, oy - y0);
+        let (x0, y0) = (x0 as i32, y0 as i32);
+        for (dx, dy, w) in [(0, 0, (1.0 - ax) * (1.0 - ay)), (1, 0, ax * (1.0 - ay)), (0, 1, (1.0 - ax) * ay), (1, 1, ax * ay)] {
+            if w <= 0.0 {
+                continue;
+            }
+            let i = *slot.entry((x0 + dx, y0 + dy)).or_insert_with(|| {
+                taps.push((x0 + dx, y0 + dy, 0.0));
+                taps.len() - 1
+            });
+            taps[i].2 += w * k;
         }
-    })
+    }
+    let reach = taps.iter().map(|t| t.0.abs().max(t.1.abs())).max().unwrap_or(0);
+    let n = src.ch;
+    let win = out.inflate(reach);
+    let ww = win.width() as usize;
+    // Premultiplied window; outside the source reads as transparent, as the sampler does.
+    let mut pw = vec![0.0f32; ww * win.height() as usize * n];
+    for y in win.y0..win.y1 {
+        for x in win.x0..win.x1 {
+            let i = ((y - win.y0) as usize * ww + (x - win.x0) as usize) * n;
+            let a = if ctx.alpha { src.get(x, y, n - 1) } else { 1.0 };
+            for c in 0..n {
+                let v = src.get(x, y, c);
+                pw[i + c] = if ctx.alpha && c < n - 1 { v * a } else { v };
+            }
+        }
+    }
+    let (ow, oh) = (out.width() as usize, out.height() as usize);
+    let mut res = vec![0.0f32; ow * oh * n];
+    let r = reach as usize;
+    for (oy, row) in res.chunks_exact_mut(ow * n).enumerate() {
+        for &(dx, dy, w) in &taps {
+            let start = ((oy + r).wrapping_add_signed(dy as isize) * ww + r.wrapping_add_signed(dx as isize)) * n;
+            for (o, v) in row.iter_mut().zip(&pw[start..start + ow * n]) {
+                *o += w * v;
+            }
+        }
+        if ctx.alpha {
+            for px in row.chunks_exact_mut(n) {
+                let a = px[n - 1];
+                for v in px.iter_mut().take(n - 1) {
+                    *v = if a > 1e-7 { *v / a } else { 0.0 };
+                }
+            }
+        }
+    }
+    res
 }
 
 pub(crate) fn radial(src: &Image, out: Rect, ctx: &Ctx, amount: f32, method: RadialMethod, center: (f32, f32)) -> Vec<f32> {
@@ -702,4 +766,34 @@ mod tests {
         img.data[i] = 0.5 / 255.0;
         assert!(surface_8bit(&img, out, &ctx, 4, 0.1, 26).is_none());
     }
+
+    #[test]
+    fn motion_kernel_matches_the_per_pixel_samples() {
+        // Noisy RGBA with some transparent pixels; the output reaches the source edge.
+        let src_rect = Rect::new(-30, -30, 50, 40);
+        let mut img = Image::new(src_rect, 4);
+        let mut s = 0x1b87_3593u32;
+        for px in img.data.as_chunks_mut::<4>().0 {
+            for v in px.iter_mut() {
+                s ^= s << 13;
+                s ^= s >> 17;
+                s ^= s << 5;
+                *v = (s % 1000) as f32 / 999.0;
+            }
+            if s.is_multiple_of(5) {
+                px[3] = 0.0;
+            }
+        }
+        let out = Rect::new(-12, -6, 30, 22);
+        for alpha in [true, false] {
+            let ctx = Ctx { bounds: src_rect, mode: crate::ColorMode::Rgb, alpha };
+            for (angle, distance) in [(0.0, 1.0), (0.0, 9.0), (30.0, 7.0), (90.0, 12.0), (-45.0, 20.0), (137.0, 33.5), (200.0, 40.0)] {
+                let fast = motion(&img, out, &ctx, angle, distance);
+                let offs = motion_offsets(angle, distance);
+                let slow = average_samples(&img, out, &ctx, |x, y, pts| pts.extend(offs.iter().map(|&(dx, dy)| (x + dx, y + dy))));
+                let err = slow.iter().zip(&fast).map(|(a, b)| (a - b).abs()).fold(0.0f32, f32::max);
+                assert!(err < 1e-5, "alpha {alpha} angle {angle} distance {distance}: max error {err}");
+            }
+        }
+    }
 }
diff --git a/crates/engine/src/variables_cmds.rs b/crates/engine/src/variables_cmds.rs
index 65e3ffee00..c6e036b0f4 100644
--- a/crates/engine/src/variables_cmds.rs
+++ b/crates/engine/src/variables_cmds.rs
@@ -164,13 +164,16 @@ fn apply_to_doc(doc: &mut Document, vars: &Variables, set: &DataSet) -> Result<(
                 }
             }
             (VarKind::TextReplacement, VarValue::Text(text)) => {
+                let snapshot = doc.clone();
                 if let Some(l) = doc.layer_mut(def.layer)
                     && let LayerContent::Text(t) = &mut l.content
                 {
                     t.text = text.clone();
-                    t.cache = None; // force re-render
                     t.runs.clear(); // re-flow as one run from the summary style
                     t.paragraphs.clear();
+                    // The compositor draws a type layer from its cache: clearing it left the
+                    // layer blank until some other edit re-rendered it (#990).
+                    crate::type_cmds::refresh(&snapshot, t);
                 }
             }
             (VarKind::PixelReplacement { method, align, clip }, VarValue::Pixels(path)) => {
diff --git a/crates/engine/src/variables_cmds/tests.rs b/crates/engine/src/variables_cmds/tests.rs
index 55ff20540d..69301add02 100644
--- a/crates/engine/src/variables_cmds/tests.rs
+++ b/crates/engine/src/variables_cmds/tests.rs
@@ -190,3 +190,25 @@ fn pixel_replacement_changes_the_layer() {
         assert!(b > r, "replacement is blue-ish: {rgba:?}");
     }
 }
+
+#[test]
+fn applied_text_is_rendered_in_the_document_and_in_exports() {
+    // Applying a text value cleared the type layer's render cache and nothing rebuilt it, so the
+    // text vanished from the canvas and from every exported file (#990).
+    let mut s = Session::new();
+    s.execute("file.new", json!({"width": 200, "height": 60, "background": "white"})).unwrap();
+    let id = s.execute("type.create", json!({"x": 4, "y": 40, "text": "HELLO", "size": 32, "color": "#000000"})).unwrap()["layer"].clone();
+    let dark = |d: &Document| photocraft_compose::render(d, d.bounds()).px.iter().filter(|p| p[0] < 0.5).count();
+    assert!(dark(doc(&s)) > 0);
+    s.execute("image.variables.define", json!({"defs": [{"name": "headline", "layer": id, "type": "textReplacement"}]})).unwrap();
+    s.execute("image.variables.dataSets", json!({"dataSets": [{"name": "row1", "values": [{"variable": "headline", "kind": "text", "value": "BYE"}]}]}))
+        .unwrap();
+    let dir = tmp("text-export");
+    let out = s.execute("file.export.dataSetsAsFiles", json!({"dir": dir, "format": "png"})).unwrap();
+    let path = out["files"][0].as_str().unwrap();
+    let exported = photocraft_io::import(path, &std::fs::read(path).unwrap()).unwrap().document;
+    assert!(dark(&exported) > 0, "the exported row keeps its text");
+    s.execute("image.applyDataSet", json!({"name": "row1"})).unwrap();
+    assert!(dark(doc(&s)) > 0, "the applied text is drawn");
+    let _ = std::fs::remove_dir_all(&dir);
+}
diff --git a/crates/io/src/psd_export.rs b/crates/io/src/psd_export.rs
index d9f9cc09e8..f8f0337339 100644
--- a/crates/io/src/psd_export.rs
+++ b/crates/io/src/psd_export.rs
@@ -244,7 +244,11 @@ impl Ex {
 
     fn encode(&self, id: i16, plane: &[u8], w: usize, h: usize) -> ChannelData {
         let depth = psd_depth(self.fmt.sample);
-        ChannelData::encode(id, self.compression(), plane, w, h, depth, self.version)
+        // Photoshop writes empty layer/mask channels as just the raw compression code.
+        // A ZIP stream for a zero-sized channel makes readers try to decompress an
+        // invalid image extent (notably psd-tools for 32-bit adjustment layers).
+        let compression = if w == 0 || h == 0 { Compression::Raw } else { self.compression() };
+        ChannelData::encode(id, compression, plane, w, h, depth, self.version)
             .or_else(|_| ChannelData::encode(id, Compression::Raw, plane, w, h, depth, self.version))
             .unwrap_or(ChannelData { id, compression: Some(Compression::Raw), data: plane.to_vec() })
     }
diff --git a/crates/io/tests/psd_empty_channels.rs b/crates/io/tests/psd_empty_channels.rs
new file mode 100644
index 0000000000..285f03cfcd
--- /dev/null
+++ b/crates/io/tests/psd_empty_channels.rs
@@ -0,0 +1,44 @@
+mod common;
+use common::Features;
+use photocraft_color::{ColorMode, SampleType};
+use photocraft_io::{ExportOptions, export};
+use photocraft_psd::{Compression, PsdFile};
+
+#[test]
+fn empty_layer_and_mask_channels_use_raw_without_a_payload() {
+    for mode in [ColorMode::Rgb, ColorMode::Grayscale] {
+        for depth in [SampleType::U8, SampleType::U16, SampleType::F32] {
+            for ext in ["out.psd", "out.psb"] {
+                let mut doc = common::gen_doc(mode, depth, Features::ALL);
+                let mut masked = common::raster("Uniform mask", doc.pixel_format(), photocraft_geom::Rect::new(0, 0, 3, 3), 1, true);
+                masked.mask = Some(photocraft_doc::LayerMask {
+                    surface: photocraft_raster::Surface::new(photocraft_color::PixelFormat::new(ColorMode::Grayscale, depth, false)),
+                    enabled: true,
+                    linked: true,
+                    density: 1.0,
+                    feather: 0.0,
+                });
+                doc.layers.push(masked);
+                let bytes = export(&doc, ext, &ExportOptions::default()).unwrap().bytes;
+                let file = PsdFile::from_bytes(&bytes).unwrap();
+                let mut empty = 0;
+                let mut empty_masks = 0;
+                for layer in file.layers() {
+                    for channel in &layer.channels {
+                        let rect = layer.channel_rect(channel.id);
+                        if rect.width() == 0 || rect.height() == 0 {
+                            empty += 1;
+                            if channel.id == -2 {
+                                empty_masks += 1;
+                            }
+                            assert_eq!(channel.compression, Some(Compression::Raw), "{mode:?} {depth:?} {ext}: {} channel {}", layer.name(), channel.id);
+                            assert!(channel.data.is_empty());
+                        }
+                    }
+                }
+                assert!(empty > 0);
+                assert!(empty_masks > 0);
+            }
+        }
+    }
+}
diff --git a/crates/psd/src/layer.rs b/crates/psd/src/layer.rs
index a0c6bd5ffb..2ecf0df6f3 100644
--- a/crates/psd/src/layer.rs
+++ b/crates/psd/src/layer.rs
@@ -214,11 +214,31 @@ impl LayerMask {
 
     /// Whether `d` (a whole mask record with mask parameters) stores the real-mask fields before
     /// the parameters, as Photoshop does. The spec's order wins when it reads as parameters
-    /// followed by padding alone (no real mask), the one layout the two orders can share.
+    /// followed by padding alone (no real mask), the one layout the two orders can share. When
+    /// both orders fit the record's length, Photoshop's is taken unless its reading is
+    /// implausible (a real-mask background that is neither 0 nor 255, or parameter flag bits
+    /// the spec does not define) while the spec's reading with a real mask is sound.
     pub(crate) fn real_before_parameters(d: &[u8]) -> bool {
+        // Parameters at `pf_at`, then 0..=3 bytes of padding, and nothing else.
         let fits =
             |pf_at: usize| d.get(pf_at).is_some_and(|&pf| (pf_at + 1 + mask_parameter_bytes(pf)..=pf_at + 4 + mask_parameter_bytes(pf)).contains(&d.len()));
-        !fits(18) && fits(36)
+        if fits(18) {
+            return false;
+        }
+        let photoshop = fits(36);
+        if !photoshop {
+            return false;
+        }
+        let known_flags = |pf: u8| pf & 0xF0 == 0;
+        let real_background_ok = |at: usize| d.get(at + 1).is_some_and(|&bg| bg == 0 || bg == 255);
+        // Photoshop's reading: real-mask fields at 18, parameters at 36.
+        let photoshop_plausible = real_background_ok(18) && d.get(36).is_some_and(|&pf| known_flags(pf));
+        // The spec's reading: parameters at 18, then the 18 real-mask bytes, then padding.
+        let spec_plausible = d.get(18).is_some_and(|&pf| {
+            let real_at = 19 + mask_parameter_bytes(pf);
+            known_flags(pf) && (real_at + 18..=real_at + 21).contains(&d.len()) && real_background_ok(real_at)
+        });
+        photoshop_plausible || !spec_plausible
     }
 
     fn parse(d: &[u8]) -> Result<Self> {
@@ -845,6 +865,45 @@ mod tests {
         assert_eq!(out, d);
     }
 
+    /// A density-only record in the spec's order (#949): the parameter flags byte at 18 says one
+    /// value byte, so the spec's reading excludes the 38-byte length only if the real mask is
+    /// ignored, while byte 36 (inside the real rectangle's `right`) is 0 and makes Photoshop's
+    /// reading fit too. Photoshop's reading puts the density (64) where a 0-or-255 background
+    /// belongs, so the spec's order wins and the density survives.
+    #[test]
+    fn density_only_spec_layout_is_not_read_as_photoshop_order() {
+        for (density, right) in [(64u8, 1u32), (200, 1), (64, 300), (1, 7)] {
+            let mut d = Vec::new();
+            Rect::from_xywh(0, 0, 1, 1).write(&mut d);
+            d.extend([255, LayerMask::FLAG_PARAMETERS]);
+            d.extend([0b0001, density]);
+            d.extend([0, 0]);
+            Rect::from_xywh(0, 0, right, 1).write(&mut d);
+            let m = LayerMask::parse(&d).unwrap();
+            assert!(!m.real_first, "density {density}, right {right}: {m:?}");
+            assert_eq!(m.parameters.unwrap().user_density, Some(density));
+            assert_eq!(m.real, Some(RealMask { flags: 0, background: 0, rect: Rect::from_xywh(0, 0, right, 1) }));
+            assert!(m.trailing.is_empty());
+            let mut out = Vec::new();
+            m.write(&mut out);
+            assert_eq!(out, d);
+        }
+        // Photoshop's order with the same lengths still reads as Photoshop's order.
+        let mut d = Vec::new();
+        Rect::from_xywh(0, 0, 1, 1).write(&mut d);
+        d.extend([255, LayerMask::FLAG_PARAMETERS]);
+        d.extend([0, 255]);
+        Rect::from_xywh(0, 0, 1, 1).write(&mut d);
+        d.extend([0b0001, 64]);
+        let m = LayerMask::parse(&d).unwrap();
+        assert!(m.real_first, "{m:?}");
+        assert_eq!(m.parameters.unwrap().user_density, Some(64));
+        assert_eq!(m.real.map(|r| r.background), Some(255));
+        let mut out = Vec::new();
+        m.write(&mut out);
+        assert_eq!(out, d);
+    }
+
     /// The spec's order (parameters, then real fields) still parses and stays byte-stable.
     #[test]
     fn real_mask_after_parameters_spec_layout() {
diff --git a/crates/psd/tests/roundtrip.rs b/crates/psd/tests/roundtrip.rs
index 8666ba3cc4..1f23ee6284 100644
--- a/crates/psd/tests/roundtrip.rs
+++ b/crates/psd/tests/roundtrip.rs
@@ -285,3 +285,30 @@ fn save_and_open() {
     assert_eq!(g, f);
     let _ = std::fs::remove_dir_all(&dir);
 }
+
+/// A density-only mask record written in the spec's order (parameters, then the real-mask
+/// fields) used to be read back in Photoshop's order, which moved the density into the real
+/// mask's background and dropped it from the parameters (#949). The model must survive the
+/// round trip, not only the bytes.
+#[test]
+fn spec_order_density_only_mask_round_trips_as_a_model() {
+    let mut f = testgen::small(Version::Psd, Compression::Raw);
+    let layer = &mut f.layers_mut()[0];
+    layer.mask = MaskData::Mask(LayerMask {
+        rect: Rect::from_xywh(0, 0, 1, 1),
+        default_color: 255,
+        flags: LayerMask::FLAG_PARAMETERS,
+        parameters: Some(MaskParameters { flags: 1, user_density: Some(64), ..Default::default() }),
+        real: Some(RealMask { flags: 0, background: 0, rect: Rect::from_xywh(0, 0, 1, 1) }),
+        trailing: vec![],
+        real_first: false,
+    });
+    // The generated 2 x 2 mask channel is replaced by one that matches the 1 x 1 rectangle.
+    let mask_channel = layer.channels.iter_mut().find(|c| c.id == -2).expect("the generated layer has a mask channel");
+    *mask_channel = ChannelData::encode(-2, Compression::Raw, &[64], 1, 1, 8, Version::Psd).unwrap();
+    let b = f.to_bytes().unwrap();
+    let g = PsdFile::from_bytes(&b).unwrap();
+    assert_eq!(g, f, "model round trip");
+    assert_eq!(g.layers()[0].decode_channel(-2, 8, Version::Psd).unwrap(), vec![64]);
+    assert_eq!(g.to_bytes().unwrap(), b, "byte stability");
+}
diff --git a/crates/ui-egui/src/canvas.rs b/crates/ui-egui/src/canvas.rs
index 7e93f02b26..259db97037 100644
--- a/crates/ui-egui/src/canvas.rs
+++ b/crates/ui-egui/src/canvas.rs
@@ -1817,12 +1817,14 @@ pub fn canvas_view(app: &mut PhotocraftApp, ui: &mut egui::Ui, idx: usize, rect:
         {
             crate::canvas_tool_menu::open_transform(app, [p.x, p.y]);
         }
+        let lasso_retracted = tool == Tool::Lasso && response.secondary_clicked() && crate::lasso_ui::undo_last_vertex(app);
         if tool == Tool::Lasso {
             crate::lasso_ui::canvas_input(app, &ctx, &xf, &response);
             (buttons.started, buttons.dragged, buttons.stopped, buttons.clicked) = (false, false, false, false);
         }
         // Right-click with the Move tool, or ⌘/Ctrl+right-click: the layers under the pointer.
         if response.secondary_clicked()
+            && !lasso_retracted
             && !transforming
             && crate::layer_pick_ui::is_gesture(tool, mods)
             && let Some(p) = response.interact_pointer_pos()
@@ -1832,6 +1834,7 @@ pub fn canvas_view(app: &mut PhotocraftApp, ui: &mut egui::Ui, idx: usize, rect:
             crate::layer_pick_ui::open(app, [p.x, p.y], d[0], d[1]);
         }
         if response.secondary_clicked()
+            && !lasso_retracted
             && !transforming
             && !crate::layer_pick_ui::is_gesture(tool, mods)
             && let Some(p) = response.interact_pointer_pos()
diff --git a/crates/ui-egui/src/control.rs b/crates/ui-egui/src/control.rs
index cf99a88276..96e8693bf6 100644
--- a/crates/ui-egui/src/control.rs
+++ b/crates/ui-egui/src/control.rs
@@ -397,8 +397,10 @@ fn dispatch(app: &mut PhotocraftApp, ctx: &egui::Context, req: &ControlRequest)
             None => err("no such dialog"),
         },
         "ui.window.open" => {
-            if let Some(d) = u("document") {
-                app.session.set_active(d as usize);
+            if let Some(d) = u("document")
+                && !app.session.set_active(d as usize)
+            {
+                return err(format!("no document {d}"));
             }
             wrap(crate::menus::invoke(app, ctx, "window.newWindowForDocument", json!({})))
         }
@@ -805,6 +807,22 @@ mod tests {
         }
     }
 
+    #[test]
+    fn ui_window_open_rejects_an_unknown_document_index() {
+        let mut app = PhotocraftApp::new(photocraft_engine::Session::new(), crate::Services::default());
+        let ctx = egui::Context::default();
+        app.run("file.new", json!({"width": 8, "height": 8})).unwrap();
+        // An out-of-range index must error instead of silently switching the active document
+        // and opening the window for whatever is active now.
+        let before = app.session.active_index();
+        let r = call(&mut app, &ctx, "ui.window.open", json!({"document": 99}));
+        assert_eq!(r["ok"], false, "{r}");
+        assert!(r["error"].as_str().unwrap().contains("no document 99"), "{r}");
+        assert_eq!(app.session.active_index(), before, "the active document is untouched");
+        // A valid index still opens the window.
+        assert_eq!(call(&mut app, &ctx, "ui.window.open", json!({"document": 0}))["ok"], true);
+    }
+
     #[test]
     fn ui_set_brush_size_dispatches_a_journaled_brush_command() {
         let mut app = PhotocraftApp::new(photocraft_engine::Session::new(), crate::Services::default());
diff --git a/crates/ui-egui/src/dialogs.rs b/crates/ui-egui/src/dialogs.rs
index 5e2dfa2898..88727983cf 100644
--- a/crates/ui-egui/src/dialogs.rs
+++ b/crates/ui-egui/src/dialogs.rs
@@ -324,7 +324,11 @@ pub fn confirm(app: &mut PhotocraftApp, id: u64) -> Result<Value, String> {
             app.filter_preview = None;
             let cmd = d.fields.get("__command").and_then(|v| v.as_str().map(str::to_string)).ok_or("dialog has no command")?;
             let (cmd, params) = crate::smart_ui::confirm_command(&d.fields, cmd, crate::filter_dialog::params_of(&d.fields));
-            app.run(&cmd, params)
+            let result = app.run(&cmd, params.clone());
+            if result.is_ok() && cmd == "view.newGuideLayout" {
+                app.ui.view.guide_layout = params;
+            }
+            result
         }
         DialogKind::LayerStyle => crate::layer_style::confirm(app, &d.fields),
         DialogKind::About | DialogKind::Error => Ok(Value::Null),
diff --git a/crates/ui-egui/src/lasso_ui.rs b/crates/ui-egui/src/lasso_ui.rs
index 8897148184..2328f748bd 100644
--- a/crates/ui-egui/src/lasso_ui.rs
+++ b/crates/ui-egui/src/lasso_ui.rs
@@ -20,6 +20,29 @@ pub fn active(app: &PhotocraftApp) -> bool {
     app.drag.as_ref().is_some_and(|d| d.tool == Tool::Lasso && d.lasso.is_some())
 }
 
+/// Between polygonal clicks, Backspace/right-click retracts the last fixed vertex.
+/// Do not affect a freehand stroke whose primary button is still held.
+pub fn waiting_for_vertex(app: &PhotocraftApp) -> bool {
+    app.ui.tool == Tool::Lasso
+        && app
+            .drag
+            .as_ref()
+            .is_some_and(|d| d.tool == Tool::Lasso && d.lasso.as_ref().is_some_and(|l| !l.down && l.document == app.session.active().map(|st| st.doc.id)))
+}
+
+pub fn undo_last_vertex(app: &mut PhotocraftApp) -> bool {
+    cancel_stale(app);
+    if !waiting_for_vertex(app) {
+        return false;
+    }
+    if app.drag.as_ref().is_some_and(|d| d.points.len() <= 1) {
+        app.drag = None;
+    } else if let Some(d) = app.drag.as_mut() {
+        d.points.pop();
+    }
+    true
+}
+
 /// A lasso drag that moves the selection (started inside it, `canvas::selection_drag_kind`):
 /// the canvas's own selection-move path handles it, this module only feeds it the events.
 fn moving_selection(app: &PhotocraftApp) -> bool {
diff --git a/crates/ui-egui/src/lasso_ui/tests.rs b/crates/ui-egui/src/lasso_ui/tests.rs
index 7639170ed8..97480f6b3f 100644
--- a/crates/ui-egui/src/lasso_ui/tests.rs
+++ b/crates/ui-egui/src/lasso_ui/tests.rs
@@ -199,3 +199,54 @@ fn a_drag_inside_the_selection_moves_it() {
     assert!(h.state().drag.is_none());
     assert_eq!(bounds(h.state()), Some(photocraft_geom::Rect::new(110, 105, 160, 145)));
 }
+
+#[test]
+fn retracting_polygonal_vertices_keeps_the_document_unchanged() {
+    let mut app = app();
+    begin(&mut app, Modifiers::NONE);
+    event(&mut app, "up", 120.0, 50.0, Modifiers::ALT);
+    assert!(waiting_for_vertex(&app));
+    let layer = app.session.active().unwrap().active_layer.unwrap();
+    assert_eq!(app.drag.as_ref().unwrap().points.len(), 3);
+    assert!(undo_last_vertex(&mut app));
+    assert_eq!(app.drag.as_ref().unwrap().points.len(), 2);
+    assert!(undo_last_vertex(&mut app));
+    assert_eq!(app.drag.as_ref().unwrap().points.len(), 1);
+    assert!(undo_last_vertex(&mut app));
+    assert!(!active(&app));
+    assert!(!undo_last_vertex(&mut app));
+    let st = app.session.active().unwrap();
+    assert!(st.doc.layer(layer).is_some());
+    assert!(st.doc.selection.is_none());
+}
+
+#[test]
+fn real_canvas_backspace_and_right_click_retract_polygonal_points() {
+    let mut h = harness();
+    mouse(&mut h, "down", 50.0, 50.0, Modifiers::NONE);
+    mouse(&mut h, "move", 120.0, 50.0, Modifiers::NONE);
+    mouse(&mut h, "up", 120.0, 50.0, Modifiers::ALT);
+    mouse(&mut h, "down", 180.0, 100.0, Modifiers::ALT);
+    mouse(&mut h, "up", 180.0, 100.0, Modifiers::ALT);
+    assert_eq!(h.state().drag.as_ref().unwrap().points.len(), 3);
+    let layer = h.state().session.active().unwrap().active_layer.unwrap();
+
+    h.event(Event::Key { key: egui::Key::Backspace, physical_key: None, pressed: true, repeat: false, modifiers: Modifiers::ALT });
+    h.run_steps(2);
+    assert_eq!(h.state().drag.as_ref().unwrap().points.len(), 2);
+    assert!(h.state().session.active().unwrap().doc.layer(layer).is_some());
+
+    let state = h.state();
+    let view = &state.ui.views[0];
+    let xf = ViewXform { rect: crate::rulers::content_rect(state, state.last_canvas_rect), zoom: view.zoom, center: view.center, flip: false };
+    let pos = xf.to_screen(155.0, 100.0);
+    h.event(Event::PointerMoved(pos));
+    h.event(Event::PointerButton { pos, button: PointerButton::Secondary, pressed: true, modifiers: Modifiers::ALT });
+    h.run_steps(1);
+    h.event(Event::PointerButton { pos, button: PointerButton::Secondary, pressed: false, modifiers: Modifiers::ALT });
+    h.run_steps(2);
+    assert_eq!(h.state().drag.as_ref().unwrap().points.len(), 1);
+    assert!(h.state().ui.canvas_tool_menu.is_none());
+    assert!(h.state().session.active().unwrap().doc.layer(layer).is_some());
+    assert!(h.state().session.active().unwrap().doc.selection.is_none());
+}
diff --git a/crates/ui-egui/src/shortcuts.rs b/crates/ui-egui/src/shortcuts.rs
index 078c9f3b7f..b413c44ea8 100644
--- a/crates/ui-egui/src/shortcuts.rs
+++ b/crates/ui-egui/src/shortcuts.rs
@@ -296,6 +296,15 @@ pub fn handle(app: &mut PhotocraftApp, ctx: &egui::Context) {
     if crate::magnetic_lasso_ui::keys(app, ctx) {
         return;
     }
+    // While placing polygonal lasso vertices, Backspace/Delete retracts the last point;
+    // it must win over the regular Edit › Clear shortcut, which edits document pixels.
+    if crate::lasso_ui::waiting_for_vertex(app) {
+        let mods = ctx.input(|i| i.modifiers);
+        if !mods.command && !mods.ctrl && !mods.shift && ctx.input_mut(|i| i.consume_key(mods, Key::Backspace) || i.consume_key(mods, Key::Delete)) {
+            crate::lasso_ui::undo_last_vertex(app);
+            return;
+        }
+    }
     // Inline type editing eats text and navigation keys; ⌘-shortcuts still reach the menus.
     let editing = crate::type_tool::handle_keys(app, ctx);
     // Registry, UI and menu-catalogue shortcuts (see [`crate::shortcut_dispatch::bindings`]).
diff --git a/crates/ui-egui/src/view_cmds.rs b/crates/ui-egui/src/view_cmds.rs
index 1184ea0910..1072b3eccf 100644
--- a/crates/ui-egui/src/view_cmds.rs
+++ b/crates/ui-egui/src/view_cmds.rs
@@ -94,6 +94,12 @@ pub struct ViewOptions {
     /// and the Middle Eastern & South Asian composer.
     pub language_features: String,
     pub middle_eastern_composer: bool,
+    /// Parameters from the last successfully applied New Guide Layout dialog.
+    pub guide_layout: Value,
+}
+
+fn default_guide_layout() -> Value {
+    json!({"columns": 8, "gutter": 20, "rows": 0, "rowGutter": 0, "margin": 0, "centerColumns": false, "clearExisting": false})
 }
 
 impl Default for ViewOptions {
@@ -112,6 +118,7 @@ impl Default for ViewOptions {
             font_preview_size: "medium".into(),
             language_features: "defaultFeatures".into(),
             middle_eastern_composer: false,
+            guide_layout: default_guide_layout(),
         }
     }
 }
@@ -846,7 +853,8 @@ fn front(app: &mut PhotocraftApp, id: &str, params: &Value) -> Option<Result<Val
             json!({"from": ["any", "rgb", "grayscale", "cmyk", "lab", "indexed", "bitmap", "duotone", "multichannel"], "to": ["rgb", "grayscale", "cmyk", "lab"]}),
         ),
         "view.newGuideLayout" => {
-            dialog(app, json!({"columns": 8, "gutter": 20, "rows": 0, "rowGutter": 0, "margin": 0, "centerColumns": false, "clearExisting": false}), json!({}))
+            let fields = app.ui.view.guide_layout.clone();
+            dialog(app, fields, json!({}))
         }
         "type.warpText" => {
             let styles: Vec<&str> = std::iter::once("none").chain(photocraft_text::warp::STYLES.iter().map(|(_, s)| *s)).collect();
diff --git a/crates/ui-egui/src/view_cmds/tests.rs b/crates/ui-egui/src/view_cmds/tests.rs
index eaabdddd66..f5519b806c 100644
--- a/crates/ui-egui/src/view_cmds/tests.rs
+++ b/crates/ui-egui/src/view_cmds/tests.rs
@@ -172,3 +172,43 @@ fn engine_commands_open_their_dialogs() {
     crate::menus::invoke_unguarded(&mut app, &ctx, "file.closeAll", json!({})).unwrap();
     assert!(app.ui.views.is_empty() && app.session.documents().is_empty());
 }
+
+#[test]
+fn new_guide_layout_remembers_successful_values_not_cancelled_edits() {
+    let (mut app, ctx) = app_with(1);
+    let first = menu(&mut app, &ctx, "view.newGuideLayout", json!({})).unwrap()["dialog"].as_u64().unwrap();
+    assert_eq!(app.ui.dialog_mut(first).unwrap().fields["columns"], 8);
+    assert_eq!(app.ui.dialog_mut(first).unwrap().fields["gutter"], 20);
+    for (key, value) in [("columns", json!(2)), ("gutter", json!(0)), ("rows", json!(2)), ("rowGutter", json!(0))] {
+        app.ui.dialog_mut(first).unwrap().fields.insert(key.into(), value);
+    }
+    crate::dialogs::confirm(&mut app, first).unwrap();
+
+    let second = menu(&mut app, &ctx, "view.newGuideLayout", json!({})).unwrap()["dialog"].as_u64().unwrap();
+    let fields = &app.ui.dialog_mut(second).unwrap().fields;
+    assert_eq!(fields["columns"], 2);
+    assert_eq!(fields["gutter"], 0);
+    assert_eq!(fields["rows"], 2);
+    assert_eq!(fields["rowGutter"], 0);
+    assert_eq!(fields["clearExisting"], false);
+    // A cancelled edit must not replace the last successfully used values.
+    app.ui.dialog_mut(second).unwrap().fields.insert("columns".into(), json!(9));
+    app.ui.close_dialog(second);
+    let third = menu(&mut app, &ctx, "view.newGuideLayout", json!({})).unwrap()["dialog"].as_u64().unwrap();
+    assert_eq!(app.ui.dialog_mut(third).unwrap().fields["columns"], 2);
+
+    // The remembered state is part of the serializable UI state.
+    let json_state = serde_json::to_value(&app.ui).unwrap();
+    assert_eq!(json_state["view"]["guide_layout"]["columns"], 2);
+    let restored: crate::state::UiState = serde_json::from_value(json_state).unwrap();
+    assert_eq!(restored.view.guide_layout["rows"], 2);
+}
+
+#[test]
+fn new_guide_layout_does_not_remember_a_failed_command() {
+    let (mut app, _) = app_with(0);
+    let id = front(&mut app, "view.newGuideLayout", &json!({})).unwrap().unwrap()["dialog"].as_u64().unwrap();
+    app.ui.dialog_mut(id).unwrap().fields.insert("columns".into(), json!(3));
+    assert!(crate::dialogs::confirm(&mut app, id).is_err());
+    assert_eq!(app.ui.view.guide_layout["columns"], 8);
+}