diff --git a/client/displayservers/Wayland/clipboard.c b/client/displayservers/Wayland/clipboard.c
index 294bfc0e..af52b896 100644
--- a/client/displayservers/Wayland/clipboard.c
+++ b/client/displayservers/Wayland/clipboard.c
@@ -1040,7 +1040,7 @@ struct ClipboardWrite
   bool                pollRegistered;
   bool                streamActive;
   bool                requesting;
-  uint8_t             buffer[KVMFR_CLIPBOARD_DATA_BYTES];
+  uint8_t             buffer[KVMFR_CLIPBOARD_REPRESENTATION_BYTES];
 };
 
 static void clipboardWriteDestroy(struct ClipboardWrite * data)
diff --git a/client/displayservers/Wayland/wayland.h b/client/displayservers/Wayland/wayland.h
index ce0f8c46..ac1f3260 100644
--- a/client/displayservers/Wayland/wayland.h
+++ b/client/displayservers/Wayland/wayland.h
@@ -316,7 +316,7 @@ struct ClipboardRead
   bool                calling;
   bool                readyPending;
   bool                eof;
-  uint8_t             buffer[KVMFR_CLIPBOARD_DATA_BYTES];
+  uint8_t             buffer[KVMFR_CLIPBOARD_REPRESENTATION_BYTES];
 };
 
 struct WCBState
diff --git a/client/displayservers/X11/clipboard.c b/client/displayservers/X11/clipboard.c
index 10f54851..6ad0f1e5 100644
--- a/client/displayservers/X11/clipboard.c
+++ b/client/displayservers/X11/clipboard.c
@@ -206,8 +206,9 @@ bool x11CBEventThread(const XEvent * xe)
             const size_t remaining = write->fileSize - (size_t)write->offset;
             if (remaining)
             {
-              const size_t chunk = remaining > KVMFR_CLIPBOARD_DATA_BYTES ?
-                KVMFR_CLIPBOARD_DATA_BYTES : remaining;
+              const size_t chunk =
+                remaining > KVMFR_CLIPBOARD_REPRESENTATION_BYTES ?
+                  KVMFR_CLIPBOARD_REPRESENTATION_BYTES : remaining;
               XChangeProperty(x11.display,
                   write->event.xselection.requestor,
                   write->event.xselection.property,
@@ -357,7 +358,8 @@ static LG_ClipboardResult x11CBWriteChunk(void * opaque,
     LG_UNLOCK(x11cb.lock);
     return LG_CLIPBOARD_RESULT_BLOCKED;
   }
-  if (offset != write->offset || size > KVMFR_CLIPBOARD_DATA_BYTES)
+  if (offset != write->offset ||
+      size > KVMFR_CLIPBOARD_REPRESENTATION_BYTES)
   {
     LG_UNLOCK(x11cb.lock);
     return LG_CLIPBOARD_RESULT_FAILED;
@@ -978,7 +980,7 @@ static void x11CBFileImportIncr(const XPropertyEvent e)
 readProperty:
   if (XGetWindowProperty(e.display, e.window, e.atom,
       x11cb.fileImport.propertyOffset,
-      (KVMFR_CLIPBOARD_DATA_BYTES + 3U) / 4U,
+      (KVMFR_CLIPBOARD_REPRESENTATION_BYTES + 3U) / 4U,
       True, AnyPropertyType, &type, &format, &itemCount, &after,
       &data) != Success || (itemCount && !data) || (!itemCount && after) ||
       type != x11cb.fileImport.target || format != 8 ||
@@ -1136,7 +1138,7 @@ readProperty:
       e.window,
       e.atom,
       x11cb.read.propertyOffset,
-      (KVMFR_CLIPBOARD_DATA_BYTES + 3U) / 4U,
+      (KVMFR_CLIPBOARD_REPRESENTATION_BYTES + 3U) / 4U,
       True,   // delete the property
       AnyPropertyType,
       &type,
@@ -1198,7 +1200,7 @@ readProperty:
     return;
   }
 
-  if (itemCount > KVMFR_CLIPBOARD_DATA_BYTES)
+  if (itemCount > KVMFR_CLIPBOARD_REPRESENTATION_BYTES)
   {
     const struct X11ClipboardRead read = clearReadNL();
     LG_UNLOCK(x11cb.lock);
diff --git a/client/tests/lgmp_clipboard_test.c b/client/tests/lgmp_clipboard_test.c
index c87686ba..1d7110f4 100644
--- a/client/tests/lgmp_clipboard_test.c
+++ b/client/tests/lgmp_clipboard_test.c
@@ -35,12 +35,18 @@
 #include <sys/mman.h>
 #include <unistd.h>
 
-#define TEST_SHM_SIZE      (8U * 1024U * 1024U)
-#define TEST_WAIT_MS       2500U
-#define TEST_QUIET_MS      50U
-#define TEST_MEMORY_MAX    128U
-#define SLOT_BYTES         \
+#define TEST_WAIT_MS          2500U
+#define TEST_QUIET_MS         50U
+#define TEST_MEMORY_MAX       128U
+#define SLOT_BYTES            \
   (sizeof(KVMFRClipboardSlotHeader) + KVMFR_CLIPBOARD_DATA_BYTES)
+#define TEST_TRANSIENT_SLOTS  4U
+#define TEST_SHM_OVERHEAD     (1024U * 1024U)
+/* Match the production inbound and outbound slot pools, retain several
+ * synthetic host DATA records at once, and leave room for LGMP metadata. */
+#define TEST_SHM_SIZE         \
+  ((2U * KVMFR_CLIPBOARD_SLOT_COUNT + TEST_TRANSIENT_SLOTS) * SLOT_BYTES + \
+    TEST_SHM_OVERHEAD)
 
 #define CHECK(x) \
   do \
@@ -1219,6 +1225,10 @@ static bool testMalformedFileData(TestState * state)
 
 static bool testFileStream(TestState * state)
 {
+  static uint8_t bytes[KVMFR_CLIPBOARD_FILE_READ_BYTES];
+  for (size_t i = 0; i < sizeof(bytes); ++i)
+    bytes[i] = (uint8_t)(i * 131U + 17U);
+
   KVMFRClipboardMessage claimRecord;
   CHECK(claim(state, 78, false, &claimRecord));
   CHECK(own(state, 78, claimRecord.generation));
@@ -1251,7 +1261,7 @@ static bool testFileStream(TestState * state)
   request.offset              = 123;
   request.size                = 42;
   request.format              = KVMFR_CLIPBOARD_FORMAT_FILES;
-  request.flags               = 3;
+  request.flags               = sizeof(bytes);
   request.token               = KVMFR_CLIPBOARD_FILE_OP_READ;
   CHECK(postRecord(state, &request,
         KVMFR_CLIPBOARD_QUEUE_MESSAGE, NULL));
@@ -1262,14 +1272,13 @@ static bool testFileStream(TestState * state)
   CHECK(descriptor.request == request.transfer);
   CHECK(descriptor.node == 42);
   CHECK(descriptor.offset == 123);
-  CHECK(descriptor.length == 3);
+  CHECK(descriptor.length == sizeof(bytes));
   CHECK(descriptor.operation == LG_CLIPBOARD_FILE_READ);
   CHECK(state->ops->fileDataBegin(state->clipboard,
-        &descriptor, 3) == LG_CLIPBOARD_RESULT_ACCEPTED);
+        &descriptor, sizeof(bytes)) == LG_CLIPBOARD_RESULT_ACCEPTED);
 
   CHECK(postGrant(state, claimRecord.generation, 1));
   CHECK(waitMemory(state, state->grantMemory[0]));
-  static const uint8_t bytes[] = { 9, 8, 7 };
   CHECK(state->ops->fileDataChunk(state->clipboard,
         &descriptor, 0, bytes, sizeof(bytes)) ==
       LG_CLIPBOARD_RESULT_ACCEPTED);
@@ -1278,16 +1287,19 @@ static bool testFileStream(TestState * state)
   const void * data;
   CHECK(checkFileCommit(state, 1, &commit, &slot, &data));
   CHECK(slot.flags == KVMFR_CLIPBOARD_FLAG_BEGIN);
-  CHECK(slot.offset == 0 && slot.sequence == 0 && slot.size == 3);
+  CHECK(slot.offset == 0 && slot.sequence == 0 &&
+      slot.size == sizeof(bytes));
+  CHECK(slot.length == sizeof(bytes));
   CHECK(memcmp(data, bytes, sizeof(bytes)) == 0);
 
   CHECK(postGrant(state, claimRecord.generation, 1));
   CHECK(waitMemory(state, state->grantMemory[0]));
   CHECK(state->ops->fileDataEnd(state->clipboard,
-        &descriptor, 3) == LG_CLIPBOARD_RESULT_ACCEPTED);
+        &descriptor, sizeof(bytes)) == LG_CLIPBOARD_RESULT_ACCEPTED);
   CHECK(checkFileCommit(state, 1, &commit, &slot, &data));
   CHECK(slot.flags == KVMFR_CLIPBOARD_FLAG_END);
-  CHECK(slot.offset == 3 && slot.sequence == 1 && slot.size == 3);
+  CHECK(slot.offset == sizeof(bytes) && slot.sequence == 1 &&
+      slot.size == sizeof(bytes));
   CHECK(slot.length == 0);
   return true;
 }
diff --git a/common/include/common/KVMFR.h b/common/include/common/KVMFR.h
index 78c6844c..915c4b2b 100644
--- a/common/include/common/KVMFR.h
+++ b/common/include/common/KVMFR.h
@@ -32,7 +32,7 @@
 #include "KVMFRInput.h"
 
 #define KVMFR_MAGIC   "KVMFR---"
-#define KVMFR_VERSION 31
+#define KVMFR_VERSION 32
 
 // Fallback used by producers that cannot report the source display's SDR
 // white level. IDD frames override this with IDDCX_METADATA2::SdrWhiteLevel.
diff --git a/common/include/common/KVMFRClipboard.h b/common/include/common/KVMFRClipboard.h
index aa87ae52..25f0bf35 100644
--- a/common/include/common/KVMFRClipboard.h
+++ b/common/include/common/KVMFRClipboard.h
@@ -26,9 +26,12 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#define KVMFR_CLIPBOARD_VERSION                2U
-#define KVMFR_CLIPBOARD_SLOT_COUNT             8U
-#define KVMFR_CLIPBOARD_DATA_BYTES             (64U * 1024U)
+#define KVMFR_CLIPBOARD_VERSION                3U
+#define KVMFR_CLIPBOARD_SLOT_COUNT             1U
+#define KVMFR_CLIPBOARD_DATA_BYTES             (1024U * 1024U)
+/* Keep text and image chunks within the core X11 request limit. File data can
+ * use the full slot without passing through XChangeProperty. */
+#define KVMFR_CLIPBOARD_REPRESENTATION_BYTES   (64U * 1024U)
 #define KVMFR_CLIPBOARD_SIZE_UNKNOWN           UINT64_MAX
 #define KVMFR_CLIPBOARD_FILE_READ_BYTES        (1024U * 1024U)
 #define KVMFR_CLIPBOARD_FILE_ROOT_NODE         UINT64_C(0)
diff --git a/idd/LGCommon/ClipboardRing.h b/idd/LGCommon/ClipboardRing.h
index 634a5ef0..23f44c02 100644
--- a/idd/LGCommon/ClipboardRing.h
+++ b/idd/LGCommon/ClipboardRing.h
@@ -26,7 +26,7 @@
 #include <stdint.h>
 
 static constexpr uint32_t LG_CLIPBOARD_MAPPING_MAGIC = 0x4c474342U;
-static constexpr uint32_t LG_CLIPBOARD_MAPPING_VERSION = 2U;
+static constexpr uint32_t LG_CLIPBOARD_MAPPING_VERSION = 3U;
 
 struct ClipboardRingSlot
 {
diff --git a/idd/LGIdd/transport/lgmp/CLGMPClipboardTransport.h b/idd/LGIdd/transport/lgmp/CLGMPClipboardTransport.h
index 0c8f8d92..773e1286 100644
--- a/idd/LGIdd/transport/lgmp/CLGMPClipboardTransport.h
+++ b/idd/LGIdd/transport/lgmp/CLGMPClipboardTransport.h
@@ -40,7 +40,7 @@ class CLGMPHost;
 class CLGMPClipboardTransport final : public IClipboardSource
 {
 private:
-  static constexpr unsigned MEMORY_COUNT = 8;
+  static constexpr unsigned MEMORY_COUNT = KVMFR_CLIPBOARD_SLOT_COUNT;
   static constexpr unsigned INTERNAL_TARGET_COUNT =
     CLGMPClipboardFiles::MAX_ACQUISITIONS +
     CLGMPClipboardFiles::MAX_REQUESTS + 3;
diff --git a/idd/LGIddHelper/CClipboardManager.cpp b/idd/LGIddHelper/CClipboardManager.cpp
index 698e699a..568ec648 100644
--- a/idd/LGIddHelper/CClipboardManager.cpp
+++ b/idd/LGIddHelper/CClipboardManager.cpp
@@ -457,7 +457,7 @@ namespace
     std::vector<uint8_t> buffer;
     try
     {
-      buffer.resize(KVMFR_CLIPBOARD_DATA_BYTES);
+      buffer.resize(KVMFR_CLIPBOARD_REPRESENTATION_BYTES);
     }
     catch (const std::bad_alloc&)
     {
@@ -1653,7 +1653,8 @@ void CClipboardManager::ProcessSendData(Work&& work)
     return;
   }
   const size_t length = static_cast<size_t>((std::min<uint64_t>)(
-    KVMFR_CLIPBOARD_DATA_BYTES, total - work.record.offset));
+    KVMFR_CLIPBOARD_REPRESENTATION_BYTES,
+    total - work.record.offset));
   std::vector<uint8_t> data;
   if (length)
   {