diff --git a/OpenNest.Data/NestRecord.cs b/OpenNest.Data/NestRecord.cs
index e77d592f..a828b968 100644
--- a/OpenNest.Data/NestRecord.cs
+++ b/OpenNest.Data/NestRecord.cs
@@ -34,6 +34,12 @@ public sealed class NestRecord
 
     public double Thickness { get; set; }
 
+    /// <summary>
+    /// The nest's units, which <see cref="Thickness"/> is in. The server reads them from the
+    /// archive like the counts; inches when the archive has none or the server predates them.
+    /// </summary>
+    public Units Units { get; set; }
+
     /// <summary>quote | toBeCut | hasBeenCut (camelCase on the wire, case-insensitive readers).</summary>
     public NestStatus Status { get; set; } = NestStatus.Quote;
 
diff --git a/OpenNest.Data/NestRecordFactory.cs b/OpenNest.Data/NestRecordFactory.cs
index fc13cb60..04923ca7 100644
--- a/OpenNest.Data/NestRecordFactory.cs
+++ b/OpenNest.Data/NestRecordFactory.cs
@@ -46,6 +46,7 @@ public static class NestRecordFactory
             Material = nest.Material?.Name ?? "",
             MaterialGrade = nest.Material?.Grade ?? "",
             Thickness = nest.Thickness,
+            Units = nest.Units,
             Status = nest.Status,
             // The trailing empty plate is the editor's new-plate slot, not a plate of the nest.
             PlateCount = PlateDisplayNumbering.DisplayedPlateCount(nest.Plates),
diff --git a/OpenNest.Server.Tests/DrawingLibraryDatabaseTests.cs b/OpenNest.Server.Tests/DrawingLibraryDatabaseTests.cs
index 372efb15..6585b4b7 100644
--- a/OpenNest.Server.Tests/DrawingLibraryDatabaseTests.cs
+++ b/OpenNest.Server.Tests/DrawingLibraryDatabaseTests.cs
@@ -22,7 +22,7 @@ public sealed class DrawingLibraryDatabaseTests
             using (var database = new NestDatabase(factory.DatabasePath, pooling: false))
                 Assert.Empty(database.QueryDrawings(new DrawingLibraryQuery { IncludeArchived = true }).Items);
             Assert.Equal(before, NestDigest(factory.DatabasePath));
-            Assert.Equal(11L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+            Assert.Equal(12L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
         }
 
         using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
@@ -43,7 +43,7 @@ public sealed class DrawingLibraryDatabaseTests
 
         using (var database = new NestDatabase(factory.DatabasePath, pooling: false))
         {
-            Assert.Equal(11L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+            Assert.Equal(12L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
             Assert.Equal(before, NestDigest(factory.DatabasePath));
             // Two distinct blobs across four revisions: the bracket's notes edit and the
             // plate both reuse the bracket's first package.
@@ -80,7 +80,7 @@ public sealed class DrawingLibraryDatabaseTests
     {
         using var factory = new ServerFactory();
         using (new NestDatabase(factory.DatabasePath, pooling: false)) { }
-        Execute(factory.DatabasePath, "PRAGMA user_version=12");
+        Execute(factory.DatabasePath, "PRAGMA user_version=13");
 
         Assert.Throws<InvalidOperationException>(() => new NestDatabase(factory.DatabasePath, pooling: false));
     }
diff --git a/OpenNest.Server.Tests/DrawingSetDatabaseTests.cs b/OpenNest.Server.Tests/DrawingSetDatabaseTests.cs
index 7265f605..86b0ffb7 100644
--- a/OpenNest.Server.Tests/DrawingSetDatabaseTests.cs
+++ b/OpenNest.Server.Tests/DrawingSetDatabaseTests.cs
@@ -22,7 +22,7 @@ public sealed class DrawingSetDatabaseTests
             using (var database = new NestDatabase(factory.DatabasePath, pooling: false))
                 Assert.Empty(database.QueryDrawingSets(new DrawingSetQuery { IncludeArchived = true }).Items);
             Assert.Equal(before, Digest(factory.DatabasePath));
-            Assert.Equal(11L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+            Assert.Equal(12L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
         }
 
         using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
@@ -47,7 +47,7 @@ public sealed class DrawingSetDatabaseTests
         Assert.Equal(before, Digest(factory.DatabasePath));
         Execute(factory.DatabasePath, "DROP TABLE ix_drawing_set_members_drawing");
         using var database = new NestDatabase(factory.DatabasePath, pooling: false);
-        Assert.Equal(11L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+        Assert.Equal(12L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
     }
 
     [Fact]
diff --git a/OpenNest.Server.Tests/MaterialListTests.cs b/OpenNest.Server.Tests/MaterialListTests.cs
index fe4fe93c..9aa24cbf 100644
--- a/OpenNest.Server.Tests/MaterialListTests.cs
+++ b/OpenNest.Server.Tests/MaterialListTests.cs
@@ -24,7 +24,7 @@ public sealed class MaterialListTests
 
         using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
 
-        Assert.Equal(11L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+        Assert.Equal(12L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
         Assert.Empty(upgraded.ListMaterials());
         Assert.Equal((" Stainless ", "304"), (upgraded.Get(nest)!.Material, upgraded.Get(nest)!.MaterialGrade));
         Assert.Equal(drawing.MaterialName, upgraded.GetDrawing(drawing.Id)!.MaterialName);
diff --git a/OpenNest.Server.Tests/NestMaterialGradeTests.cs b/OpenNest.Server.Tests/NestMaterialGradeTests.cs
index 0e04840b..f51502bb 100644
--- a/OpenNest.Server.Tests/NestMaterialGradeTests.cs
+++ b/OpenNest.Server.Tests/NestMaterialGradeTests.cs
@@ -74,7 +74,7 @@ public sealed class NestMaterialGradeTests
         Assert.Equal("Stainless", record.Material);
         Assert.Equal("", record.MaterialGrade);
         Assert.Equal("", Assert.Single(upgraded.History(id, 0, 10)!.Items).MaterialGrade);
-        Assert.Equal(11L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+        Assert.Equal(12L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
     }
 
     private static NestRecord Record(string name, string material, string grade) => new()
diff --git a/OpenNest.Server.Tests/NestUnitsTests.cs b/OpenNest.Server.Tests/NestUnitsTests.cs
new file mode 100644
index 00000000..b2262637
--- /dev/null
+++ b/OpenNest.Server.Tests/NestUnitsTests.cs
@@ -0,0 +1,109 @@
+using System.Net.Http.Json;
+using System.Text.Json;
+using Microsoft.Data.Sqlite;
+using OpenNest.Data;
+
+namespace OpenNest.Server.Tests;
+
+/// <summary>
+/// Nest records carry the archive's units, which their thickness is in, so a list of nests can
+/// tell a millimeter nest from an inch one without reading each archive.
+/// </summary>
+public sealed class NestUnitsTests
+{
+    [Fact]
+    public async Task Upload_TakesUnitsFromTheArchive_NotTheClientsClaim()
+    {
+        using var factory = new ServerFactory();
+        using var client = factory.CreateClient();
+        var nest = NestApiTests.SyntheticNest();
+        nest.Units = Units.Millimeters;
+        nest.Thickness = 6.35;
+
+        using var created = await client.PostAsync("/api/nests",
+            NestRevisionTests.Body(new NestRecord { Name = "Metric", Units = Units.Inches }, NestApiTests.Archive(nest)));
+        var json = await created.Content.ReadAsStringAsync();
+        var id = JsonDocument.Parse(json).RootElement.GetProperty("id").GetGuid();
+
+        Assert.Equal("millimeters", JsonDocument.Parse(json).RootElement.GetProperty("units").GetString());
+        using var listed = JsonDocument.Parse(await client.GetStringAsync("/api/nests/query"));
+        var item = Assert.Single(listed.RootElement.GetProperty("items").EnumerateArray());
+        Assert.Equal("millimeters", item.GetProperty("units").GetString());
+        Assert.Equal(6.35, item.GetProperty("thickness").GetDouble());
+        using var record = JsonDocument.Parse(await client.GetStringAsync($"/api/nests/{id}"));
+        Assert.Equal("millimeters", record.RootElement.GetProperty("units").GetString());
+    }
+
+    [Fact]
+    public void MetadataOnlySave_KeepsTheArchivesUnits()
+    {
+        using var factory = new ServerFactory();
+        using var database = new NestDatabase(factory.DatabasePath, pooling: false);
+        var id = Guid.NewGuid();
+        var created = database.Insert(id, Record("Metric", Units.Millimeters), [1]);
+
+        var updated = database.UpdateMetadata(id, Record("Metric renamed", Units.Inches), created.Revision)!;
+
+        Assert.Equal(Units.Millimeters, updated.Units);
+        Assert.Equal([Units.Millimeters, Units.Millimeters], database.History(id, 0, 10)!.Items.Select(r => r.Units));
+    }
+
+    [Fact]
+    public void Version11Database_ReadsEachStoredArchivesUnits()
+    {
+        using var factory = new ServerFactory();
+        var metric = Guid.NewGuid();
+        var inch = Guid.NewGuid();
+        var unreadable = Guid.NewGuid();
+        var metricNest = NestApiTests.SyntheticNest();
+        metricNest.Units = Units.Millimeters;
+        using (var database = new NestDatabase(factory.DatabasePath, pooling: false))
+        {
+            var created = database.Insert(metric, Record("Metric", Units.Inches), NestApiTests.Archive(metricNest));
+            database.UpdateMetadata(metric, Record("Metric renamed", Units.Inches), created.Revision);
+            database.Insert(inch, Record("Inch", Units.Inches), NestApiTests.Archive(NestApiTests.SyntheticNest()));
+            database.Insert(unreadable, Record("Broken", Units.Inches), [1]);
+        }
+        Execute(factory.DatabasePath, """
+            ALTER TABLE nests DROP COLUMN units;
+            ALTER TABLE nest_revisions DROP COLUMN units;
+            PRAGMA user_version=11;
+            """);
+
+        using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
+
+        Assert.Equal(Units.Millimeters, upgraded.Get(metric)!.Units);
+        Assert.Equal([Units.Millimeters, Units.Millimeters], upgraded.History(metric, 0, 10)!.Items.Select(r => r.Units));
+        Assert.Equal(Units.Inches, upgraded.Get(inch)!.Units);
+        Assert.Equal(Units.Inches, upgraded.Get(unreadable)!.Units);
+        Assert.Equal(12L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+    }
+
+    private static NestRecord Record(string name, Units units) => new()
+    {
+        Name = name,
+        Material = "Steel",
+        Thickness = 0.25,
+        Units = units,
+        DateCreated = new DateTime(2026, 1, 1),
+        DateModified = new DateTime(2026, 1, 2),
+    };
+
+    private static void Execute(string path, string sql)
+    {
+        using var connection = new SqliteConnection($"Data Source={path};Pooling=False");
+        connection.Open();
+        using var command = connection.CreateCommand();
+        command.CommandText = sql;
+        command.ExecuteNonQuery();
+    }
+
+    private static object? Scalar(string path, string sql)
+    {
+        using var connection = new SqliteConnection($"Data Source={path};Pooling=False");
+        connection.Open();
+        using var command = connection.CreateCommand();
+        command.CommandText = sql;
+        return command.ExecuteScalar();
+    }
+}
diff --git a/OpenNest.Server.Tests/SetReleaseDrawingTests.cs b/OpenNest.Server.Tests/SetReleaseDrawingTests.cs
index 3c09519e..26c25774 100644
--- a/OpenNest.Server.Tests/SetReleaseDrawingTests.cs
+++ b/OpenNest.Server.Tests/SetReleaseDrawingTests.cs
@@ -151,7 +151,7 @@ public sealed class SetReleaseDrawingTests
 
         using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
 
-        Assert.Equal(11L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+        Assert.Equal(12L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
         var kept = upgraded.GetRelease(releaseId)!;
         Assert.Empty(kept.Drawings);
         Assert.Equal(((Guid?)kit.Id, drawing, 2), (kept.Nests[0].Items.Single().SetId, kept.Nests[0].Items.Single().DrawingId, kept.Nests[0].Items.Single().Quantity));
diff --git a/OpenNest.Server.Tests/SetReleaseTests.cs b/OpenNest.Server.Tests/SetReleaseTests.cs
index db7afb90..fd8e4493 100644
--- a/OpenNest.Server.Tests/SetReleaseTests.cs
+++ b/OpenNest.Server.Tests/SetReleaseTests.cs
@@ -294,7 +294,7 @@ public sealed class SetReleaseTests
 
         using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
 
-        Assert.Equal(11L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+        Assert.Equal(12L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
         Assert.Equal(0L, Scalar(factory.DatabasePath, "SELECT COUNT(*) FROM sqlite_master WHERE name LIKE 'set_release%' OR name LIKE 'ix_set_release%'"));
         var release = upgraded.GetRelease(releaseId)!;
         Assert.Equal(("Legacy notes", "Legacy operator", false), (release.Notes, release.ReleasedBy, release.IsUndone));
diff --git a/OpenNest.Server/NestArchive.cs b/OpenNest.Server/NestArchive.cs
index 27da30d8..14820162 100644
--- a/OpenNest.Server/NestArchive.cs
+++ b/OpenNest.Server/NestArchive.cs
@@ -20,7 +20,7 @@ internal static class NestArchive
     private static readonly JsonSerializerOptions Options = new(JsonSerializerDefaults.Web);
 
     /// <summary>
-    /// Overwrites the record's plate count, part count, material and thickness with the
+    /// Overwrites the record's plate count, part count, material, thickness and units with the
     /// archive's own. Returns an error when the bytes are not a readable nest archive.
     /// </summary>
     public static string? Apply(NestRecord record, byte[] file)
@@ -33,6 +33,7 @@ internal static class NestArchive
         // falls back to the plate defaults. Thickness falls back when not positive.
         record.Material = (nest.Material ?? defaults.Material)?.Name ?? "";
         record.Thickness = nest.Thickness > 0 ? nest.Thickness : defaults.Thickness;
+        record.Units = UnitsOf(nest);
 
         // NestReader drops parts whose drawing is missing. Cut-off parts are never written as
         // parts, so every remaining part counts.
@@ -106,8 +107,7 @@ internal static class NestArchive
             })
             .ToList();
 
-        // NestReader: absent or unknown units keep the nest default, inches.
-        var units = Enum.TryParse<Units>(nest.Units, ignoreCase: true, out var parsed) ? parsed : Units.Inches;
+        var units = UnitsOf(nest);
 
         sheets = new NestSheets
         {
@@ -121,6 +121,13 @@ internal static class NestArchive
         return null;
     }
 
+    /// <summary>The archive's units, for backfilling records stored before they were kept; inches when unreadable.</summary>
+    public static Units ReadUnits(byte[] file) => Read(file, out var nest) is null ? UnitsOf(nest) : Units.Inches;
+
+    // NestReader: absent or unknown units keep the nest default, inches.
+    private static Units UnitsOf(NestJson nest) =>
+        Enum.TryParse<Units>(nest.Units, ignoreCase: true, out var parsed) ? parsed : Units.Inches;
+
     private static string? Read(byte[] file, out NestJson nest)
     {
         nest = null!;
diff --git a/OpenNest.Server/NestDatabase.cs b/OpenNest.Server/NestDatabase.cs
index d558db46..f1c1e242 100644
--- a/OpenNest.Server/NestDatabase.cs
+++ b/OpenNest.Server/NestDatabase.cs
@@ -154,10 +154,10 @@ public sealed partial class NestDatabase : IDisposable
             command.Transaction = transaction;
             command.CommandText = """
                 INSERT INTO nests (id, name, customer, dateCreated, dateModified, material,
-                    materialGrade, thickness, status, plateCount, partCount, comments, madeBy,
+                    materialGrade, thickness, units, status, plateCount, partCount, comments, madeBy,
                     fileSize, savedAt, file)
                 VALUES ($id, $name, $customer, $dateCreated, $dateModified, $material,
-                    $materialGrade, $thickness, $status, $plateCount, $partCount, $comments,
+                    $materialGrade, $thickness, $units, $status, $plateCount, $partCount, $comments,
                     $madeBy, $fileSize, $savedAt, $file)
                 """;
             AddRecordParameters(command, id, record, file, updateFile: true);
@@ -186,9 +186,10 @@ public sealed partial class NestDatabase : IDisposable
             if (current.Revision != expectedRevision) throw new RevisionConflictException(current);
             if (file is null)
             {
-                // The counts describe the archive, which a metadata-only save leaves unchanged.
+                // The counts and units describe the archive, which a metadata-only save leaves unchanged.
                 record.PlateCount = current.PlateCount;
                 record.PartCount = current.PartCount;
+                record.Units = current.Units;
             }
             file ??= GetFile(id)!;
             if (SameMetadata(current, record) && GetFile(id)!.AsSpan().SequenceEqual(file)) return current;
@@ -210,7 +211,7 @@ public sealed partial class NestDatabase : IDisposable
                 UPDATE nests SET
                     name = $name, customer = $customer, dateCreated = $dateCreated,
                     dateModified = $dateModified, material = $material,
-                    materialGrade = $materialGrade, thickness = $thickness, status = $status, plateCount = $plateCount,
+                    materialGrade = $materialGrade, thickness = $thickness, units = $units, status = $status, plateCount = $plateCount,
                     partCount = $partCount, comments = $comments, madeBy = $madeBy,
                     savedAt = $savedAt, revision = $revision, restoredFromRevision=$source{fileClause}
                 WHERE id = $id
@@ -320,7 +321,7 @@ public sealed partial class NestDatabase : IDisposable
     private static bool SameMetadata(NestRecord a, NestRecord b) =>
         a.Name == b.Name && a.Customer == b.Customer && a.DateCreated == b.DateCreated &&
         a.DateModified == b.DateModified && a.Material == b.Material && a.MaterialGrade == b.MaterialGrade &&
-        a.Thickness == b.Thickness && a.Status == b.Status && a.PlateCount == b.PlateCount && a.PartCount == b.PartCount &&
+        a.Thickness == b.Thickness && a.Units == b.Units && a.Status == b.Status && a.PlateCount == b.PlateCount && a.PartCount == b.PartCount &&
         a.Comments == b.Comments && a.MadeBy == b.MadeBy;
 
     private void Snapshot(Guid id, SqliteTransaction transaction)
@@ -341,7 +342,7 @@ public sealed partial class NestDatabase : IDisposable
             command.Transaction = transaction;
             command.CommandText = "PRAGMA user_version";
             var version = (long)command.ExecuteScalar()!;
-            if (version > 11) throw new InvalidOperationException("Database schema is newer than this server.");
+            if (version > 12) throw new InvalidOperationException("Database schema is newer than this server.");
             if (version == 0)
             {
                 command.CommandText = """
@@ -426,10 +427,47 @@ public sealed partial class NestDatabase : IDisposable
                 command.CommandText = ReleaseUpgradeToV11;
                 command.ExecuteNonQuery();
             }
+            if (version < 12)
+                AddUnits(command);
             transaction.Commit();
         }
     }
 
+    // v12: records keep the archive's units, which their thickness is in. Every stored archive,
+    // current or historical, is read once so millimeter nests are not reported as inches.
+    private static void AddUnits(SqliteCommand command)
+    {
+        foreach (var table in new[] { "nests", "nest_revisions" })
+        {
+            command.CommandText = $"SELECT COUNT(*) FROM pragma_table_info('{table}') WHERE name='units'";
+            if ((long)command.ExecuteScalar()! == 0)
+            {
+                command.CommandText = $"ALTER TABLE {table} ADD COLUMN units TEXT NOT NULL DEFAULT 'Inches'";
+                command.ExecuteNonQuery();
+            }
+            var millimeters = new List<long>();
+            command.CommandText = $"SELECT rowid, file FROM {table}";
+            using (var reader = command.ExecuteReader())
+            {
+                while (reader.Read())
+                {
+                    if (NestArchive.ReadUnits((byte[])reader.GetValue(1)) == Units.Millimeters)
+                        millimeters.Add(reader.GetInt64(0));
+                }
+            }
+            command.CommandText = $"UPDATE {table} SET units='Millimeters' WHERE rowid=$rowid";
+            var rowid = command.Parameters.Add("$rowid", SqliteType.Integer);
+            foreach (var id in millimeters)
+            {
+                rowid.Value = id;
+                command.ExecuteNonQuery();
+            }
+            command.Parameters.Clear();
+        }
+        command.CommandText = "PRAGMA user_version=12";
+        command.ExecuteNonQuery();
+    }
+
     /// <summary>Checks the live connection without exposing storage error details.</summary>
     public bool IsHealthy()
     {
@@ -464,7 +502,7 @@ public sealed partial class NestDatabase : IDisposable
     private const string RecordColumns = """
         id, name, customer, dateCreated, dateModified, material, thickness,
         status, plateCount, partCount, comments, madeBy, fileSize, savedAt, revision, deleted, restoredFromRevision,
-        materialGrade
+        materialGrade, units
         """;
 
     // Case-insensitive (ASCII) substring over the text columns and the status's stored
@@ -557,6 +595,7 @@ public sealed partial class NestDatabase : IDisposable
         command.Parameters.AddWithValue("$material", record.Material);
         command.Parameters.AddWithValue("$materialGrade", record.MaterialGrade);
         command.Parameters.AddWithValue("$thickness", record.Thickness);
+        command.Parameters.AddWithValue("$units", record.Units.ToString());
         command.Parameters.AddWithValue("$status", record.Status.ToString());
         command.Parameters.AddWithValue("$plateCount", record.PlateCount);
         command.Parameters.AddWithValue("$partCount", record.PartCount);
@@ -594,6 +633,7 @@ public sealed partial class NestDatabase : IDisposable
             Deleted = reader.GetInt32(first + 15) != 0,
             RestoredFromRevision = reader.IsDBNull(first + 16) ? null : reader.GetInt32(first + 16),
             MaterialGrade = reader.GetString(first + 17),
+            Units = Enum.TryParse<Units>(reader.GetString(first + 18), true, out var units) ? units : Units.Inches,
         };
     }
 }
diff --git a/docs/nest-storage.md b/docs/nest-storage.md
index 6c50e274..4f4f90dc 100644
--- a/docs/nest-storage.md
+++ b/docs/nest-storage.md
@@ -83,6 +83,7 @@ entry, never programs or geometry, and takes the archive-derived fields below fr
 | `material` | string | Material name (type), e.g. `Stainless`. Read from the uploaded archive (nest material, else plate defaults' on an explicit null); a metadata-only PUT may change it, and the desktop applies the record's value when opening the nest. |
 | `materialGrade` | string | Optional; default blank. Older servers drop it. A blank grade on a record saved before schema v8 is treated as unrecorded: opening keeps the archive's grade while the material name matches. |
 | `thickness` | number | Read from the uploaded archive (nest thickness, else plate defaults' when not positive); editable like `material`. |
+| `units` | `"inches"` \| `"millimeters"` | The nest's units, which `thickness` is in. Server-computed from the uploaded archive (absent or unknown values are inches, as `NestReader` reads them); ignored on upload and kept by a metadata-only PUT. Schema v12 read every stored archive, current and historical, to fill it. Older servers omit it, which readers take as inches. |
 | `status` | `"draft"` \| `"quote"` \| `"toBeCut"` \| `"hasBeenCut"` | Default `quote`. |
 | `plateCount` / `partCount` | integer | Server-computed from the uploaded archive (non-cutoff parts only; a trailing plate with no parts or cut-offs is not counted); ignored on upload and kept by a metadata-only PUT. |
 | `comments` | string | |
@@ -247,7 +248,8 @@ only the requested page of metadata (never archive bytes):
   can merge into): `status` (`draft`, `quote`, `toBeCut` or `hasBeenCut`),
   `material` and `materialGrade` (compared by `SharedListNames.Key`, so case and
   spacing are ignored; a present but blank `materialGrade` asks for nests with no
-  grade) and `thickness` (a number, zero or greater, matched at four decimals).
+  grade) and `thickness` (a number, zero or greater, matched at four decimals in
+  each nest's own units).
   The client sends them only when set, so plain browsing still works against
   servers without them.
 - `offset` (default 0, at least 0) and `limit` (default 100, 1 to 500).