diff --git a/src/app/commands/styleprops.rs b/src/app/commands/styleprops.rs
index fe427276b..c44add7b9 100644
--- a/src/app/commands/styleprops.rs
+++ b/src/app/commands/styleprops.rs
@@ -645,46 +645,96 @@ impl OpenCADStudio {
             // ── SETBYLAYER — clear color/linetype/lineweight overrides ────
             // Resets the selected entities' direct property overrides back to
             // ByLayer so they follow their layer again.
+            "SETBYLAYERMODE" => {
+                let command = crate::modules::draw::modify::setbylayer::ModeCommand;
+                self.command_line.push_info(&command.prompt());
+                self.tabs[i].active_cmd = Some(Box::new(command));
+            }
+            value if value.starts_with("SETBYLAYERMODE ") => {
+                if let Ok(mode) = value.trim_start_matches("SETBYLAYERMODE ").trim().parse::<u8>() {
+                    crate::modules::draw::modify::setbylayer::set_mode(mode);
+                } else { self.command_line.push_error("SETBYLAYERMODE requires an integer from 0 to 255."); }
+            }
             "SETBYLAYER" => {
-                if self.tabs[i].scene.selected.is_empty() {
-                    use crate::modules::draw::select::SelectObjectsCommand;
-                    let selection = SelectObjectsCommand::new("SETBYLAYER");
-                    self.command_line.push_info(&selection.prompt());
-                    self.tabs[i].active_cmd = Some(Box::new(selection));
-                    return Some(self.finish_dispatch(cmd));
+                let command = crate::modules::draw::modify::setbylayer::SetByLayerCommand::new(
+                    self.tabs[i].scene.selected.iter().copied().collect(),
+                );
+                self.command_line.push_info(&command.prompt());
+                self.tabs[i].active_cmd = Some(Box::new(command));
+            }
+            cmd if cmd.starts_with("SETBYLAYER_APPLY ") => {
+                let flags: Vec<_> = cmd.split_whitespace().skip(1).collect();
+                if flags.len() != 2 || flags.iter().any(|flag| !matches!(*flag, "0" | "1")) {
+                    return Some(Task::none());
                 }
-                let handles: Vec<_> = self.tabs[i]
+                let mask = crate::modules::draw::modify::setbylayer::mode();
+                let change_byblock = flags[0] == "1";
+                let include_blocks = flags[1] == "1";
+                let mut handles: Vec<_> = self.tabs[i]
                     .scene
                     .selected_entities()
                     .into_iter()
                     .map(|(h, _)| h)
                     .filter(|handle| !self.tabs[i].scene.is_layer_locked(*handle))
                     .collect();
+                if include_blocks {
+                    let mut visited: std::collections::HashSet<_> = handles.iter().copied().collect();
+                    let mut index = 0;
+                    while index < handles.len() {
+                        let children = match self.tabs[i].scene.document.get_entity(handles[index]) {
+                            Some(acadrust::EntityType::Insert(insert)) => self.tabs[i].scene.document
+                                .block_records.get(&insert.block_name)
+                                .map(|block| block.entity_handles.clone()).unwrap_or_default(),
+                            _ => Vec::new(),
+                        };
+                        for child in children {
+                            if visited.insert(child) && !self.tabs[i].scene.is_layer_locked(child) {
+                                handles.push(child);
+                            }
+                        }
+                        index += 1;
+                    }
+                }
                 if handles.is_empty() {
                     self.command_line
                         .push_error(crate::t!("SETBYLAYER: select entities first.").as_ref());
                 } else {
+                    let has_changes = handles.iter().any(|handle| {
+                        self.tabs[i].scene.document.get_entity(*handle).is_some_and(|entity| {
+                            let mut common = entity.common().clone();
+                            crate::modules::draw::modify::setbylayer::apply_mask(
+                                &mut common, mask, change_byblock,
+                            )
+                        })
+                    });
+                    if !has_changes {
+                        self.command_line.push_output(
+                            crate::t!("SETBYLAYER: no properties required changes.").as_ref(),
+                        );
+                        return Some(Task::none());
+                    }
                     self.push_undo_snapshot(i, "SETBYLAYER");
-                    let mut changed = 0usize;
+                    let mut changed = Vec::new();
                     for handle in &handles {
                         if let Some(entity) = self.tabs[i].scene.document.get_entity_mut(*handle) {
-                            let common = entity.common_mut();
-                            common.color = acadrust::types::Color::ByLayer;
-                            common.color_name = None;
-                            common.color_book_handle = None;
-                            common.linetype = "ByLayer".to_string();
-                            common.line_weight = acadrust::types::LineWeight::ByLayer;
-                            changed += 1;
+                            if crate::modules::draw::modify::setbylayer::apply_mask(
+                                entity.common_mut(), mask, change_byblock,
+                            ) {
+                                changed.push(*handle);
+                            }
                         }
                     }
                     self.tabs[i].dirty = true;
-                    let changes: Vec<_> = handles
-                        .into_iter()
+                    let changes: Vec<_> = changed
+                        .iter()
+                        .copied()
                         .map(|handle| (handle, crate::scene::ChangeKind::Modified))
                         .collect();
                     self.tabs[i].scene.bump_entities(&changes);
+                    self.refresh_properties();
                     self.command_line.push_output(crate::tf!(
-                        "SETBYLAYER: reset {changed} entity/entities to ByLayer."
+                        "SETBYLAYER: reset {} entity/entities to ByLayer.",
+                        changed.len()
                     ).as_ref());
                 }
             }
diff --git a/src/modules/draw/modify/mod.rs b/src/modules/draw/modify/mod.rs
index 4964db414..651e4df12 100644
--- a/src/modules/draw/modify/mod.rs
+++ b/src/modules/draw/modify/mod.rs
@@ -21,6 +21,7 @@ pub mod refedit;
 pub mod reverse;
 pub mod rotate;
 pub mod scale;
+pub mod setbylayer;
 pub mod spline_ops;
 pub mod splinedit;
 pub mod stretch;
diff --git a/src/modules/draw/modify/setbylayer.rs b/src/modules/draw/modify/setbylayer.rs
new file mode 100644
index 000000000..d266ab542
--- /dev/null
+++ b/src/modules/draw/modify/setbylayer.rs
@@ -0,0 +1,153 @@
+use acadrust::Handle;
+use glam::DVec3;
+use crate::command::{CadCommand, CmdOption, CmdResult};
+
+static MODE: std::sync::atomic::AtomicU8 = std::sync::atomic::AtomicU8::new(255);
+pub fn mode() -> u8 { MODE.load(std::sync::atomic::Ordering::Relaxed) }
+pub fn set_mode(value: u8) { MODE.store(value, std::sync::atomic::Ordering::Relaxed); }
+
+pub fn apply_mask(common: &mut acadrust::entities::EntityCommon, mask: u8, change_byblock: bool) -> bool {
+    let before = common.clone();
+    if mask & 1 != 0 && (change_byblock || common.color != acadrust::types::Color::ByBlock) {
+        common.color = acadrust::types::Color::ByLayer;
+        common.color_name = None;
+        common.color_book_handle = None;
+    }
+    if mask & 2 != 0 && (change_byblock || !common.linetype.eq_ignore_ascii_case("ByBlock")) {
+        common.linetype = "ByLayer".to_string();
+        common.linetype_handle = None;
+    }
+    if mask & 4 != 0 && (change_byblock || common.line_weight != acadrust::types::LineWeight::ByBlock) {
+        common.line_weight = acadrust::types::LineWeight::ByLayer;
+    }
+    if mask & 8 != 0 && (change_byblock || common.material_flags != 1) {
+        common.material_flags = 0;
+        common.material_handle = None;
+    }
+    if mask & 16 != 0 && (change_byblock || common.plotstyle_flags != 1) {
+        common.plotstyle_flags = 0;
+        common.plotstyle_handle = None;
+    }
+    if mask & 128 != 0 && (change_byblock || common.transparency != acadrust::types::Transparency::BY_BLOCK) {
+        common.transparency = acadrust::types::Transparency::BY_LAYER;
+    }
+    *common != before
+}
+
+enum Step { Selection, ByBlock, Blocks }
+
+pub struct SetByLayerCommand {
+    selected: Vec<Handle>,
+    step: Step,
+    change_byblock: bool,
+    include_blocks: bool,
+}
+
+impl SetByLayerCommand {
+    pub fn new(selected: Vec<Handle>) -> Self {
+        let step = if selected.is_empty() { Step::Selection } else { Step::ByBlock };
+        Self { selected, step, change_byblock: mode() & 32 != 0, include_blocks: mode() & 64 != 0 }
+    }
+
+    fn answer(&mut self, yes: bool) -> CmdResult {
+        match self.step {
+            Step::ByBlock => {
+                self.change_byblock = yes;
+                self.step = Step::Blocks;
+                CmdResult::NeedPoint
+            }
+            Step::Blocks => {
+                let flags = (mode() & !(32 | 64)) | if self.change_byblock { 32 } else { 0 } | if yes { 64 } else { 0 };
+                set_mode(flags);
+                CmdResult::Relaunch(
+                format!("SETBYLAYER_APPLY {} {}", u8::from(self.change_byblock), u8::from(yes)),
+                self.selected.clone(),
+            ) },
+            Step::Selection => CmdResult::NeedPoint,
+        }
+    }
+}
+
+impl CadCommand for SetByLayerCommand {
+    fn name(&self) -> &'static str { "SETBYLAYER" }
+    fn prompt(&self) -> String {
+        match self.step {
+            Step::Selection => "Select objects:".into(),
+            Step::ByBlock => format!("Change ByBlock to ByLayer? [Yes/No] <{}>:", if self.change_byblock { "Yes" } else { "No" }),
+            Step::Blocks => format!("Include blocks? [Yes/No] <{}>:", if self.include_blocks { "Yes" } else { "No" }),
+        }
+    }
+    fn is_selection_gathering(&self) -> bool { matches!(self.step, Step::Selection) }
+    fn on_selection_complete(&mut self, handles: Vec<Handle>) -> CmdResult {
+        self.selected = handles;
+        CmdResult::NeedPoint
+    }
+    fn options(&self) -> Vec<CmdOption> {
+        if self.is_selection_gathering() { Vec::new() }
+        else { vec![CmdOption::new("Yes", "Y"), CmdOption::new("No", "N")] }
+    }
+    fn wants_text_input(&self) -> bool { !self.is_selection_gathering() }
+    fn on_point(&mut self, _: DVec3) -> CmdResult { CmdResult::NeedPoint }
+    fn on_enter(&mut self) -> CmdResult {
+        if self.is_selection_gathering() {
+            if self.selected.is_empty() { CmdResult::Cancel }
+            else { self.step = Step::ByBlock; CmdResult::NeedPoint }
+        } else { self.answer(if matches!(self.step, Step::ByBlock) { self.change_byblock } else { self.include_blocks }) }
+    }
+    fn on_text_input(&mut self, text: &str) -> Option<CmdResult> {
+        Some(match text.trim().to_uppercase().as_str() {
+            "Y" | "YES" => self.answer(true),
+            "N" | "NO" => self.answer(false),
+            _ => CmdResult::NeedPoint,
+        })
+    }
+}
+
+pub struct ModeCommand;
+impl CadCommand for ModeCommand {
+    fn name(&self) -> &'static str { "SETBYLAYERMODE" }
+    fn prompt(&self) -> String { format!("Enter new value for SETBYLAYERMODE <{}>:", mode()) }
+    fn wants_text_input(&self) -> bool { true }
+    fn on_point(&mut self, _: DVec3) -> CmdResult { CmdResult::NeedPoint }
+    fn on_enter(&mut self) -> CmdResult { CmdResult::Cancel }
+    fn on_text_input(&mut self, text: &str) -> Option<CmdResult> {
+        Some(if let Ok(value) = text.trim().parse::<u8>() {
+            set_mode(value); CmdResult::Cancel
+        } else { CmdResult::NeedPoint })
+    }
+}
+inventory::submit!(crate::command::CommandRegistration { names: &["SETBYLAYERMODE"] });
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use acadrust::entities::EntityCommon;
+    use acadrust::types::{Color, Transparency};
+
+    #[test]
+    fn mask_changes_only_requested_properties() {
+        let mut common = EntityCommon::default();
+        common.color = Color::from_index(3);
+        common.linetype = "DASHED".into();
+        common.transparency = Transparency::from_percent(40.0);
+
+        assert!(apply_mask(&mut common, 1 | 128, false));
+        assert_eq!(common.color, Color::ByLayer);
+        assert_eq!(common.linetype, "DASHED");
+        assert_eq!(common.transparency, Transparency::BY_LAYER);
+    }
+
+    #[test]
+    fn byblock_values_are_kept_unless_requested() {
+        let mut common = EntityCommon::default();
+        common.color = Color::ByBlock;
+        common.linetype = "ByBlock".into();
+        common.transparency = Transparency::BY_BLOCK;
+
+        assert!(!apply_mask(&mut common, 1 | 2 | 128, false));
+        assert!(apply_mask(&mut common, 1 | 2 | 128, true));
+        assert_eq!(common.color, Color::ByLayer);
+        assert_eq!(common.linetype, "ByLayer");
+        assert_eq!(common.transparency, Transparency::BY_LAYER);
+    }
+}