diff --git a/packages/@atjson/util/test/extract-slices.test.ts b/packages/@atjson/util/test/extract-slices.test.ts
index 2259c28b7..3fc3fa50a 100644
--- a/packages/@atjson/util/test/extract-slices.test.ts
+++ b/packages/@atjson/util/test/extract-slices.test.ts
@@ -426,6 +426,7 @@ describe("extractSlices", () => {
             id: "M00000003",
             type: "italic",
             range: "(6..7]",
+            attributes: {},
           },
         ],
       };
@@ -437,6 +438,7 @@ describe("extractSlices", () => {
       expect(doc.marks).toMatchInlineSnapshot(`
         [
           {
+            "attributes": {},
             "end": 2,
             "id": "M00000003",
             "range": "(1..2]",
@@ -562,6 +564,7 @@ describe("extractSlices", () => {
             id: "M00000003",
             type: "italic",
             range: "(5..6]",
+            attributes: {},
           },
         ],
       };
@@ -573,6 +576,7 @@ describe("extractSlices", () => {
       expect(doc.marks).toMatchInlineSnapshot(`
         [
           {
+            "attributes": {},
             "end": 2,
             "id": "M00000003",
             "range": "(1..2]",
@@ -583,6 +587,217 @@ describe("extractSlices", () => {
       `);
     });
 
+    test("marks overlapping multiple slices", () => {
+      const original = {
+        text: "ABCBD",
+        blocks: [
+          {
+            id: "B00000000",
+            type: "paragraph",
+            parents: [],
+            selfClosing: false,
+            attributes: {},
+          },
+        ],
+        marks: [
+          {
+            id: "M00000000",
+            type: "slice",
+            range: "(1..5]",
+            attributes: {
+              refs: ["B00000000"],
+            },
+          },
+          {
+            id: "M00000001",
+            type: "slice",
+            range: "(2..5]",
+            attributes: {
+              refs: ["B00000000"],
+            },
+          },
+          {
+            id: "M00000002",
+            type: "slice",
+            range: "(3..4]",
+            attributes: {
+              refs: ["B00000000"],
+            },
+          },
+          {
+            id: "M00000003",
+            type: "italic",
+            range: "(5..6]",
+            attributes: {},
+          },
+          {
+            id: "M00000004",
+            type: "bold",
+            range: "(1..6]",
+            attributes: {},
+          },
+        ],
+      };
+
+      let [doc, slices] = extractSlices(original);
+      expect(slices.get("M00000000")?.text).toEqual("A");
+      expect(slices.get("M00000000")?.marks).toHaveLength(0);
+      expect(slices.get("M00000001")?.text).toEqual("BB");
+      expect(slices.get("M00000001")?.marks).toHaveLength(0);
+      expect(slices.get("M00000002")?.text).toEqual("C");
+      expect(slices.get("M00000002")?.marks).toHaveLength(0);
+      expect(doc.text).toEqual("D");
+      expect(doc.marks).toMatchInlineSnapshot(`
+        [
+          {
+            "attributes": {},
+            "end": 2,
+            "id": "M00000003",
+            "range": "(1..2]",
+            "start": 1,
+            "type": "italic",
+          },
+          {
+            "attributes": {},
+            "end": 2,
+            "id": "M00000004",
+            "range": "(1..2]",
+            "start": 1,
+            "type": "bold",
+          },
+        ]
+      `);
+    });
+
+    test("marks crossing multiple slices but contained in none are dropped", () => {
+      const original = {
+        text: "ABCBD",
+        blocks: [
+          {
+            id: "B00000000",
+            type: "paragraph",
+            parents: [],
+            selfClosing: false,
+            attributes: {},
+          },
+        ],
+        marks: [
+          {
+            id: "M00000000",
+            type: "slice",
+            range: "(1..5]",
+            attributes: {
+              refs: ["B00000000"],
+            },
+          },
+          {
+            id: "M00000001",
+            type: "slice",
+            range: "(2..5]",
+            attributes: {
+              refs: ["B00000000"],
+            },
+          },
+          {
+            id: "M00000002",
+            type: "slice",
+            range: "(3..5]",
+            attributes: {
+              refs: ["B00000000"],
+            },
+          },
+          {
+            id: "M00000003",
+            type: "italic",
+            range: "(3..5]",
+            attributes: {},
+          },
+        ],
+      };
+
+      let [doc, slices] = extractSlices(original);
+      expect(slices.get("M00000000")?.text).toEqual("A");
+      expect(slices.get("M00000000")?.marks).toHaveLength(0);
+      expect(slices.get("M00000001")?.text).toEqual("B");
+      expect(slices.get("M00000001")?.marks).toHaveLength(0);
+      expect(slices.get("M00000002")?.text).toEqual("CB");
+      expect(slices.get("M00000002")?.marks).toMatchInlineSnapshot(`
+        [
+          {
+            "attributes": {},
+            "end": 3,
+            "id": "M00000002-M00000003",
+            "range": "(1..3]",
+            "start": 1,
+            "type": "italic",
+          },
+        ]
+      `);
+      expect(doc.text).toEqual("D");
+      expect(doc.marks).toHaveLength(0);
+    });
+
+    test("marks contained in multiple slices", () => {
+      const original = {
+        text: "ABCBD",
+        blocks: [
+          {
+            id: "B00000000",
+            type: "paragraph",
+            parents: [],
+            selfClosing: false,
+            attributes: {},
+          },
+        ],
+        marks: [
+          {
+            id: "M00000000",
+            type: "slice",
+            range: "(1..5]",
+            attributes: {
+              refs: ["B00000000"],
+            },
+          },
+          {
+            id: "M00000001",
+            type: "slice",
+            range: "(2..5]",
+            attributes: {
+              refs: ["B00000000"],
+            },
+          },
+          {
+            id: "M00000002",
+            type: "slice",
+            range: "(3..5]",
+            attributes: {
+              refs: ["B00000000"],
+            },
+          },
+          {
+            id: "M00000003",
+            type: "italic",
+            // this mark is split by multiple slices so it is not
+            // fully contained in any of them. Currently this means
+            // it is not a part of any slice. In the future we may split
+            // this mark like we do blocks
+            range: "(1..5]",
+            attributes: {},
+          },
+        ],
+      };
+
+      let [doc, slices] = extractSlices(original);
+      expect(slices.get("M00000000")?.text).toEqual("A");
+      expect(slices.get("M00000000")?.marks).toHaveLength(0);
+      expect(slices.get("M00000001")?.text).toEqual("B");
+      expect(slices.get("M00000001")?.marks).toHaveLength(0);
+      expect(slices.get("M00000002")?.text).toEqual("CB");
+      expect(slices.get("M00000002")?.marks).toHaveLength(0);
+      expect(doc.text).toEqual("D");
+      expect(doc.marks).toHaveLength(0);
+    });
+
     test("hanging overlapping slices", () => {
       const original = {
         text: "ABCD",
@@ -616,6 +831,7 @@ describe("extractSlices", () => {
             id: "M00000002",
             type: "italic",
             range: "(4..5]",
+            attributes: {},
           },
         ],
       };
@@ -626,6 +842,7 @@ describe("extractSlices", () => {
       expect(doc.marks).toMatchInlineSnapshot(`
         [
           {
+            "attributes": {},
             "end": 2,
             "id": "M00000002",
             "range": "(1..2]",