What is an X-sheet (exposure sheet) and how do Dragonframe, OpenToonz and Toon Boom Harmony each lay out frames, layers/exposures, holds and exposure edits?

OpenToonz 1.7.1 docs and Harmony 25 Premium menu reference (bytes match producer pins) describe the Xsheet as a frame-row by layer-column timing grid with editable exposure; Harmony defaults to overwrite and offers insert mode. Curator qualifications: Dragonframe 2025 manual strand (auto-built sheet from capture, 48-frame print default, holds, CSV export) not reinspected: PDF exceeds curator fetch cap; carried as producer statements. Cross-tool authorship synthesis (F0) partly depends on the Dragonframe strand. Curator amendment CA-AM-0089 (2026-10-22): Hold lifted. Verified on the producer copy C2-B48-D5/work/df2025.pdf (sha256 dda5b3fb9678fdbc, equal to the pin, 11,432,915 bytes, over the curator cap). Same-host curator receipt: dragonframe.com/robots.txt GET 2026-10-22, HTTP 200, sha256 c911fce5a7789896. Text extracted by the curator with pdftotext. 'Using Dragonframe 2025', Chapter 12 'Using the X-Sheet': the X-Sheet 'is your scene's timing roadmap', also called an exposure sheet or dope sheet. 'As you update your scene, the X-Sheet updates automatically', and 'As you capture frames' it shows what has been shot and which frame and exposure is next. 'When printed, each page contains 48 frames'. The sheet 'is set at 48 frames long' and grows as you shoot past frame 48; the length is preset in Scene Settings or the Start/End Frame fields. Frames can be held ('If you wish to repeat a frame, or hold it') and cut/copied/pasted from the X-Sheet. 'Exporting the X-Sheet as a CSV' (p. 215): FILE|EXPORT X-SHEET writes a CSV that 'will include all audio track reading information, camera move data and notes'. The producer did not report that FILE|IMPORT|X-SHEET DATA imports CSV with column selection. F0 (Dragonframe fills the grid from capture while OpenToonz/Harmony expect entered timing) is now supported on all three manuals. Dragonframe still allows hand edits and imports, so 'fills from capture' describes the default flow, not an exclusive one. Limitations: Two of three manuals reinspected. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://www.dragonframe.com/download/Using%20Dragonframe%202025.pdf",
      "note": "Working in Xsheet/Timeline intro; Xsheet View Menu: Insert Mode"
    },
    {
      "url": "https://opentoonz.readthedocs.io/en/latest/working_in_xsheet.html",
      "note": "Working in Xsheet/Timeline intro; Xsheet View Menu: Insert Mode"
    },
    {
      "url": "https://docs.toonboom.com/help/harmony-25/premium/reference/menu/view/xsheet-view-menu.html",
      "note": "Working in Xsheet/Timeline intro; Xsheet View Menu: Insert Mode"
    }
  ]
}