diff --git a/OpenNest.Core/AppliedCuttingWork.cs b/OpenNest.Core/AppliedCuttingWork.cs
new file mode 100644
index 00000000..0a1acc98
--- /dev/null
+++ b/OpenNest.Core/AppliedCuttingWork.cs
@@ -0,0 +1,93 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace OpenNest;
+
+/// <summary>Existing cutting work on a set of plates: applied lead-ins and cut-offs.</summary>
+/// <param name="LeadInParts">Real parts carrying applied lead-ins (locked ones included).</param>
+/// <param name="LockedLeadInParts">Of those, parts whose lead-ins are locked.</param>
+/// <param name="CutOffs">Cut-off definitions.</param>
+/// <param name="PlateNumbers">Display numbers of the plates holding any of it, ascending.</param>
+public sealed record AppliedCuttingWorkSummary(int LeadInParts, int LockedLeadInParts, int CutOffs,
+    IReadOnlyList<int> PlateNumbers)
+{
+    public bool HasExistingWork => LeadInParts > 0 || CutOffs > 0;
+
+    /// <summary>Operator text for the cutting planner's warning banner; empty when nothing exists.</summary>
+    public string Describe()
+    {
+        if (!HasExistingWork)
+            return string.Empty;
+        var found = new List<string>();
+        if (LeadInParts > 0)
+            found.Add($"lead-ins on {Count(LeadInParts, "part")}"
+                + (LockedLeadInParts > 0 ? $" ({LockedLeadInParts} locked)" : string.Empty));
+        if (CutOffs > 0)
+            found.Add(Count(CutOffs, "cut-off"));
+        var plates = PlateNumbers.Count == 1 ? "plate " : "plates ";
+        var kept = new List<string>();
+        if (LockedLeadInParts > 0)
+            kept.Add("locked lead-ins");
+        if (CutOffs > 0)
+            kept.Add("existing cut-offs");
+        return $"ALREADY APPLIED: {string.Join(" and ", found)} on {plates}{string.Join(", ", PlateNumbers)}."
+            + (LeadInParts > LockedLeadInParts ? " Planning recalculates unlocked lead-ins." : string.Empty)
+            + (kept.Count > 0 ? $" Planning keeps {string.Join(" and ", kept)} unchanged." : string.Empty)
+            + " Clear them to recalculate everything from scratch.";
+    }
+
+    private static string Count(int value, string noun) => $"{value} {noun}{(value == 1 ? string.Empty : "s")}";
+}
+
+/// <summary>Finds and clears applied lead-ins and cut-offs so a plan can recalculate them.</summary>
+public static class AppliedCuttingWork
+{
+    /// <summary>
+    /// Counts applied lead-ins on real parts and cut-off definitions. Definitions in
+    /// <paramref name="ignoredCutOffs"/> (for example ones staged by the caller) are not counted.
+    /// </summary>
+    public static AppliedCuttingWorkSummary Summarize(IReadOnlyList<Plate> plates,
+        IReadOnlyList<int> plateNumbers = null, IEnumerable<CutOff> ignoredCutOffs = null)
+    {
+        ArgumentNullException.ThrowIfNull(plates);
+        if (plateNumbers != null && plateNumbers.Count != plates.Count)
+            throw new ArgumentException("Give one display number per plate.", nameof(plateNumbers));
+        var ignored = new HashSet<CutOff>(ignoredCutOffs ?? [], ReferenceEqualityComparer.Instance);
+        int leads = 0, locked = 0, cutOffs = 0;
+        var numbers = new SortedSet<int>();
+        for (var index = 0; index < plates.Count; index++)
+        {
+            var plate = plates[index] ?? throw new ArgumentException("Plates must not be null.", nameof(plates));
+            var plateLeads = plate.Parts.Where(p => !p.BaseDrawing.IsCutOff && p.HasManualLeadIns).ToArray();
+            var plateCutOffs = plate.CutOffs.Count(c => !ignored.Contains(c));
+            leads += plateLeads.Length;
+            locked += plateLeads.Count(p => p.LeadInsLocked);
+            cutOffs += plateCutOffs;
+            if (plateLeads.Length > 0 || plateCutOffs > 0)
+                numbers.Add(plateNumbers?[index] ?? index + 1);
+        }
+        return new(leads, locked, cutOffs, numbers.ToArray());
+    }
+
+    /// <summary>
+    /// Removes every applied lead-in (locked ones too) from real parts and every cut-off with
+    /// its cut-off parts, and forgets each plate's recorded cutting parameters. Part poses,
+    /// order and quantities are unchanged. Returns what was cleared.
+    /// </summary>
+    public static AppliedCuttingWorkSummary Clear(IReadOnlyList<Plate> plates, IReadOnlyList<int> plateNumbers = null)
+    {
+        var cleared = Summarize(plates, plateNumbers);
+        foreach (var plate in plates)
+        {
+            foreach (var part in plate.Parts.Where(p => !p.BaseDrawing.IsCutOff && p.HasManualLeadIns).ToArray())
+                part.RemoveLeadIns();
+            plate.CutOffs.Clear();
+            for (var index = plate.Parts.Count - 1; index >= 0; index--)
+                if (plate.Parts[index].BaseDrawing.IsCutOff)
+                    plate.Parts.RemoveAt(index);
+            plate.CuttingParameters = null;
+        }
+        return cleared;
+    }
+}
diff --git a/OpenNest.Core/AutomaticCutOffBatch.cs b/OpenNest.Core/AutomaticCutOffBatch.cs
index 1c04ae3a..6e429506 100644
--- a/OpenNest.Core/AutomaticCutOffBatch.cs
+++ b/OpenNest.Core/AutomaticCutOffBatch.cs
@@ -42,11 +42,19 @@ public static class AutomaticCutOffBatch
     /// Returned plans describe the fresh proposal, not preview parts to accept into a plate.
     /// </summary>
     public static IReadOnlyList<AutomaticCutOffPlan> Apply(IReadOnlyList<Plate> plates,
+        AutomaticCutOffOptions options, CutOffSettings settings) => Stage(plates, options, settings).Plans;
+
+    /// <summary>
+    /// Applies like <see cref="Apply"/>, but keeps the recovery state so the caller can take the
+    /// new cut-offs back off again (<see cref="AutomaticCutOffStaging.Revert"/>) when the work they
+    /// were added for is abandoned. A blocked batch changes nothing and has nothing to revert.
+    /// </summary>
+    public static AutomaticCutOffStaging Stage(IReadOnlyList<Plate> plates,
         AutomaticCutOffOptions options, CutOffSettings settings)
     {
         var plans = Create(plates, options, settings);
         if (plans.Any(plan => plan.HasBlockingDiagnostics))
-            return plans;
+            return new AutomaticCutOffStaging(plans, []);
 
         var restoreActions = new List<(int PlateNumber, Action Restore)>();
         try
@@ -66,21 +74,7 @@ public static class AutomaticCutOffBatch
         }
         catch (Exception applyError)
         {
-            var rollbackErrors = new List<Exception>();
-            for (var index = restoreActions.Count - 1; index >= 0; index--)
-            {
-                var saved = restoreActions[index];
-                try
-                {
-                    saved.Restore();
-                }
-                catch (Exception rollbackError)
-                {
-                    // A broken observer on one plate must not prevent recovery of the others.
-                    rollbackErrors.Add(new InvalidOperationException(
-                        $"Plate {saved.PlateNumber}: {rollbackError.Message}", rollbackError));
-                }
-            }
+            var rollbackErrors = RestoreAll(restoreActions);
             if (rollbackErrors.Count > 0)
                 throw new InvalidOperationException(
                     $"Apply failed: {applyError.Message}\nRestoring cut-offs also failed: "
@@ -91,7 +85,27 @@ public static class AutomaticCutOffBatch
             throw new InvalidOperationException(
                 $"No new cut-offs were retained; original cut-offs were restored. {applyError.Message}", applyError);
         }
-        return plans;
+        return new AutomaticCutOffStaging(plans, restoreActions);
+    }
+
+    internal static List<Exception> RestoreAll(IReadOnlyList<(int PlateNumber, Action Restore)> restoreActions)
+    {
+        var errors = new List<Exception>();
+        for (var index = restoreActions.Count - 1; index >= 0; index--)
+        {
+            var saved = restoreActions[index];
+            try
+            {
+                saved.Restore();
+            }
+            catch (Exception rollbackError)
+            {
+                // A broken observer on one plate must not prevent recovery of the others.
+                errors.Add(new InvalidOperationException(
+                    $"Plate {saved.PlateNumber}: {rollbackError.Message}", rollbackError));
+            }
+        }
+        return errors;
     }
 
     private static Action CaptureRestore(Plate plate, AutomaticCutOffPlan plan)
@@ -117,3 +131,52 @@ public static class AutomaticCutOffBatch
         };
     }
 }
+
+/// <summary>
+/// Cut-offs added by <see cref="AutomaticCutOffBatch.Stage"/> that are still provisional: either
+/// <see cref="Keep"/> them once the work they belong to is committed, or <see cref="Revert"/> them.
+/// Owner-thread only, like the plates it changed.
+/// </summary>
+public sealed class AutomaticCutOffStaging
+{
+    private IReadOnlyList<(int PlateNumber, Action Restore)> restoreActions;
+
+    internal AutomaticCutOffStaging(IReadOnlyList<AutomaticCutOffPlan> plans,
+        IReadOnlyList<(int PlateNumber, Action Restore)> restoreActions)
+    {
+        Plans = plans;
+        this.restoreActions = restoreActions;
+        Definitions = plans.SelectMany(plan => plan.HasBlockingDiagnostics ? [] : plan.Definitions).ToArray();
+    }
+
+    /// <summary>The fresh plans, one per plate in the order given.</summary>
+    public IReadOnlyList<AutomaticCutOffPlan> Plans { get; }
+
+    /// <summary>True when any plate blocked the batch; then nothing was added.</summary>
+    public bool IsBlocked => Plans.Any(plan => plan.HasBlockingDiagnostics);
+
+    /// <summary>The definitions this staging added (empty when blocked or nothing was needed).</summary>
+    public IReadOnlyList<CutOff> Definitions { get; }
+
+    /// <summary>True while the added cut-offs can still be reverted.</summary>
+    public bool CanRevert => restoreActions.Count > 0;
+
+    /// <summary>Makes the added cut-offs permanent; a later <see cref="Revert"/> does nothing.</summary>
+    public void Keep() => restoreActions = [];
+
+    /// <summary>
+    /// Removes the added cut-offs and restores each touched plate's previous cut-off programs and
+    /// sequence. Real parts are not touched. Runs once; throws if any plate could not be restored.
+    /// </summary>
+    public void Revert()
+    {
+        var actions = restoreActions;
+        restoreActions = [];
+        var errors = AutomaticCutOffBatch.RestoreAll(actions);
+        if (errors.Count > 0)
+            throw new InvalidOperationException(
+                "Removing the added cut-offs failed: " + string.Join("; ", errors.Select(e => e.Message))
+                + "\nThe nest may be incomplete; review it before saving or cutting.",
+                new AggregateException(errors));
+    }
+}
diff --git a/OpenNest.Tests/CutOffs/PlannerCutOffStagingTests.cs b/OpenNest.Tests/CutOffs/PlannerCutOffStagingTests.cs
new file mode 100644
index 00000000..8ec5bd84
--- /dev/null
+++ b/OpenNest.Tests/CutOffs/PlannerCutOffStagingTests.cs
@@ -0,0 +1,190 @@
+using OpenNest.CNC;
+using OpenNest.CNC.CuttingPlanning;
+using OpenNest.Engine.CuttingPlanning;
+using OpenNest.Geometry;
+using OpenNest.Tests.CuttingPlanning;
+
+namespace OpenNest.Tests.CutOffs;
+
+/// <summary>The cutting planner's existing-work banner, its Clear button and staged automatic cut-offs.</summary>
+public class PlannerCutOffStagingTests
+{
+    private static readonly AutomaticCutOffOptions Options = new() { Spacing = 35 };
+
+    [Fact]
+    public void Summarize_CountsAppliedLeadInsLockedPartsAndCutOffs_ButNotStagedOnes()
+    {
+        var nest = new Nest();
+        var first = Plate(nest, Clean("a", 1, 1), Clean("b", 12, 1), Clean("c", 23, 1));
+        var second = Plate(nest, Clean("d", 1, 1));
+        var third = Plate(nest, Clean("e", 1, 1));
+        Lead(first.Parts[0], locked: true);
+        Lead(first.Parts[2], locked: false);
+        var manual = new CutOff(new Vector(60, 0), CutOffAxis.Vertical);
+        var staged = new CutOff(new Vector(80, 0), CutOffAxis.Vertical);
+        third.CutOffs.Add(manual);
+        third.CutOffs.Add(staged);
+        third.RegenerateCutOffs(new CutOffSettings());
+
+        var summary = AppliedCuttingWork.Summarize([first, second, third], [4, 5, 6], [staged]);
+
+        Assert.Equal(2, summary.LeadInParts);
+        Assert.Equal(1, summary.LockedLeadInParts);
+        Assert.Equal(1, summary.CutOffs); // Cut-off parts are not lead-in parts; the staged line is ignored.
+        Assert.Equal([4, 6], summary.PlateNumbers);
+        Assert.True(summary.HasExistingWork);
+        Assert.Equal("ALREADY APPLIED: lead-ins on 2 parts (1 locked) and 1 cut-off on plates 4, 6."
+            + " Planning recalculates unlocked lead-ins. Planning keeps locked lead-ins and existing cut-offs unchanged."
+            + " Clear them to recalculate everything from scratch.", summary.Describe());
+
+        var clean = AppliedCuttingWork.Summarize([second], null, null);
+        Assert.False(clean.HasExistingWork);
+        Assert.Equal(string.Empty, clean.Describe());
+        Assert.False(AppliedCuttingWork.Summarize([third], null, third.CutOffs).HasExistingWork);
+    }
+
+    [Fact]
+    public void Clear_RemovesLeadInsAndCutOffs_KeepsPosesOrderAndQuantities()
+    {
+        var nest = new Nest();
+        var plate = Plate(nest, Clean("a", 1, 1), Clean("b", 12, 1), Clean("c", 40, 1));
+        var parameters = ExplicitContourTests.Parameters();
+        Assert.Equal(CuttingCommitStatus.Applied,
+            CuttingPlanBatch.Capture([plate], parameters, preservePartOrder: true).Plan().Apply().Status);
+        plate.Parts[1].LeadInsLocked = true;
+        plate.CutOffs.Add(new CutOff(new Vector(30, 0), CutOffAxis.Vertical));
+        plate.RegenerateCutOffs(new CutOffSettings());
+        var real = plate.Parts.Where(p => !p.BaseDrawing.IsCutOff).ToArray();
+        var poses = real.Select(p => (p.Location, p.Rotation)).ToArray();
+        var quantities = real.Select(p => p.BaseDrawing.Quantity.Nested).ToArray();
+        Assert.All(real, p => Assert.True(p.HasManualLeadIns));
+        Assert.NotNull(plate.CuttingParameters);
+
+        var cleared = AppliedCuttingWork.Clear([plate], [3]);
+
+        Assert.Equal((3, 1, 1), (cleared.LeadInParts, cleared.LockedLeadInParts, cleared.CutOffs));
+        Assert.Equal([3], cleared.PlateNumbers);
+        Assert.Equal(real, plate.Parts.ToArray());
+        Assert.Empty(plate.CutOffs);
+        Assert.Null(plate.CuttingParameters);
+        Assert.All(real, p => Assert.False(p.HasManualLeadIns || p.LeadInsLocked));
+        Assert.All(real, p => Assert.True(ProgramContent.Equal(p.BaseDrawing.Program, p.Program)));
+        Assert.Equal(poses, real.Select(p => (p.Location, p.Rotation)));
+        Assert.Equal(quantities, real.Select(p => p.BaseDrawing.Quantity.Nested));
+        Assert.False(AppliedCuttingWork.Summarize([plate]).HasExistingWork);
+    }
+
+    [Fact]
+    public void Stage_Revert_RestoresTheEarlierCutOffsAndSequenceExactly()
+    {
+        var nest = new Nest();
+        var plate = Plate(nest, Clean("a", 1, 1), Clean("b", 40, 1));
+        var settings = new CutOffSettings();
+        var manual = new CutOff(new Vector(75, 0), CutOffAxis.Vertical);
+        plate.CutOffs.Add(manual);
+        plate.RegenerateCutOffs(settings);
+        var manualPart = plate.Parts[^1];
+        plate.Parts.Remove(manualPart);
+        plate.Parts.Insert(0, manualPart);
+        var before = plate.Parts.ToArray();
+        var manualProgram = manual.Drawing.Program;
+
+        var staging = AutomaticCutOffBatch.Stage([plate], Options, settings);
+
+        Assert.False(staging.IsBlocked);
+        Assert.True(staging.CanRevert);
+        Assert.NotEmpty(staging.Definitions);
+        Assert.Equal(1 + staging.Definitions.Count, plate.CutOffs.Count);
+        Assert.Equal(plate.CutOffs.Count, plate.Parts.Count(p => p.BaseDrawing.IsCutOff));
+
+        staging.Revert();
+
+        Assert.False(staging.CanRevert);
+        Assert.Same(manual, Assert.Single(plate.CutOffs));
+        Assert.Same(manualProgram, manual.Drawing.Program);
+        Assert.Equal(before, plate.Parts.ToArray());
+        staging.Revert(); // Runs once.
+        Assert.Equal(before, plate.Parts.ToArray());
+    }
+
+    [Fact]
+    public void Stage_Keep_LeavesTheCutOffsInPlace_AndABlockedBatchChangesNothing()
+    {
+        var nest = new Nest();
+        var plate = Plate(nest, Clean("a", 1, 1), Clean("b", 40, 1));
+        var settings = new CutOffSettings();
+        var staging = AutomaticCutOffBatch.Stage([plate], Options, settings);
+        var staged = plate.CutOffs.ToArray();
+
+        staging.Keep();
+        staging.Revert();
+
+        Assert.False(staging.CanRevert);
+        Assert.Equal(staged, plate.CutOffs.ToArray());
+        Assert.NotEmpty(staged);
+
+        var other = Plate(nest, Clean("c", 1, 1), Clean("d", 40, 1));
+        var limited = new CutOff(new Vector(35, 0), CutOffAxis.Vertical) { EndLimit = 2 };
+        other.CutOffs.Add(limited);
+        var parts = other.Parts.ToArray();
+        var blocked = AutomaticCutOffBatch.Stage([other], Options, settings);
+
+        Assert.True(blocked.IsBlocked);
+        Assert.False(blocked.CanRevert);
+        Assert.Empty(blocked.Definitions);
+        Assert.Same(limited, Assert.Single(other.CutOffs));
+        Assert.Equal(parts, other.Parts.ToArray());
+    }
+
+    [Fact]
+    public void StagedCutOffs_AreSequencedByThePlannerBeforeThePartsTheyCross_AndSurviveApply()
+    {
+        var nest = new Nest();
+        var plate = Plate(nest, Clean("a", 1, 1), Clean("b", 30, 1), Clean("c", 30, 40), Clean("d", 60, 20));
+        var settings = new CutOffSettings();
+        var staging = AutomaticCutOffBatch.Stage([plate], Options, settings);
+        Assert.NotEmpty(staging.Definitions);
+
+        // The planner judges crossings on the bounds it captured, before lead-ins widen them.
+        var captured = plate.Parts.ToDictionary(p => p, p => p.BoundingBox, ReferenceEqualityComparer.Instance);
+        var proposal = CuttingPlanBatch.Capture([plate], ExplicitContourTests.Parameters(), preservePartOrder: false).Plan();
+        Assert.True(proposal.CanApply);
+        Assert.Equal(CuttingCommitStatus.Applied, proposal.Apply().Status);
+        staging.Keep();
+
+        Assert.Equal(staging.Definitions, plate.CutOffs.ToArray());
+        var order = plate.Parts.ToList();
+        var bounds = plate.BoundingBox(includeParts: false);
+        var crossings = 0;
+        foreach (var definition in plate.CutOffs)
+        {
+            var cutIndex = order.FindIndex(p => ReferenceEquals(p.BaseDrawing, definition.Drawing));
+            Assert.True(cutIndex >= 0);
+            foreach (var part in order.Where(p => !p.BaseDrawing.IsCutOff))
+            {
+                Assert.True(part.HasManualLeadIns);
+                if (!CuttingDependencyGraph.CutOffCrosses(definition.Axis, definition.Position,
+                        definition.StartLimit, definition.EndLimit, captured[part], bounds))
+                    continue;
+                crossings++;
+                Assert.True(cutIndex < order.IndexOf(part)); // Planner rule: a crossing cut-off goes first.
+            }
+        }
+        Assert.True(crossings > 0); // The fixture must exercise cut-off precedence.
+    }
+
+    private static void Lead(Part part, bool locked) =>
+        Assert.True(part.RestoreLeadInProgram((Program)part.Program.Clone(), locked));
+
+    private static Plate Plate(Nest nest, params Part[] parts)
+    {
+        var plate = nest.CreatePlate();
+        plate.Size = new Size(100, 100);
+        foreach (var part in parts)
+            plate.Parts.Add(part);
+        return plate;
+    }
+
+    private static Part Clean(string name, double x, double y) =>
+        new(new Drawing(name, ExplicitContourTests.Square(false)), new Vector(x, y));
+}