The Kneeboard Mask — every document you fly with, on one board

Approach charts, aircraft data, start-up procedures, your squadron's checklist — load them all into a single kneeboard and switch between them with named tabs. Page through them with a HOTAS button, bookmark the pages you actually need in the air, and scribble notes on a blank page with a graphics tablet or your phone.

A kneeboard mask is a document panel that floats in your cockpit. It can hold your own PDFs and images, and — in DCS — the sim's own kneeboard pages, the mission briefing, a moving map and more. Every source becomes a tab along the top of the board, and each tab remembers its own page. Everything works in DCS and MSFS; the DCS-specific sources simply stay unticked if you fly something else.

You need
  • PassthroughForge v2.97.344 or newer (multiple named PDF tabs)
  • Your documents as PDF files, or as a set of images (PNG / JPG / BMP)
  • Optional: a spare HOTAS button or key for paging and tab switching in flight
  • Optional, for handwritten notes: a graphics tablet (OpenTabletDriver) or your phone
In this guide
  1. Create the kneeboard mask
  2. Load your PDFs as named tabs
  3. The DCS sources explained
  4. Paging, tab strip and placement
  5. Shortcuts for the cockpit
  6. Bookmarks — your in-flight shortlist
  7. Notes — write on your kneeboard
  8. Tips & limits
1

Create the kneeboard mask

Click + Add Mask (Wizard) at the top left of PassthroughForge and pick the last entry, Kneeboard / Documents. It sits under the DCS auto-sources heading, but that is only where it lives in the list — a kneeboard full of your own PDFs needs no DCS at all and works exactly the same in MSFS.

The Add new mask wizard with Kneeboard / Documents selected at the bottom of the list.
Step 1 — pick Kneeboard / Documents and click Create.

The new mask appears as a [Doc] tab in the mask bar and spawns in front of you at a readable portrait size. It starts with the DCS Aircraft source ticked; if you don't fly DCS, simply untick it once you have added your own documents.

The page is a document, not a canvas While a document is loaded the painting tools are disabled — anything you drew would be lost on the next page turn. Notes have their own tab for exactly that reason (see step 7).
2

Load your PDFs as named tabs

In the mask's Kneeboard / Documents panel you'll find the PDF tabs list. Click + Add PDF tab... and pick a document. Repeat for every document you want on the board — up to 8 tabs.

  • One PDF per tab. Every page of that PDF becomes a page of the tab.
  • Or a set of images: multi-select several PNG/JPG files (Ctrl+click) and they become one tab with one image per page, in alphabetical order.
  • Rename it: the text field holds the tab name shown in VR. It starts as the file name — short names read much better on the board ("Approach LOWI" beats "LOWI_RNP26_charts_rev4").
  • Reorder with the ▲ / ▼ arrows, remove with X (that only removes the tab — your PDF file is untouched).
The Kneeboard / Documents panel with three named PDF tabs, the DCS source checkboxes and the active-tab selector.
The whole kneeboard panel: three PDF tabs with their own names, page counts on the right, the DCS sources below, and the Active tab selector at the bottom.
Every tab remembers its own page Leave the approach chart on page 3, jump to the checklist, come back — you are on page 3 again. That is what makes a multi-PDF board usable in flight instead of a page-hunting exercise.

One last step that is easy to forget: press Save Profile. Tabs, names, order and the page you were on are stored with the profile, so the board comes back exactly like this tomorrow.

3

The DCS sources explained

Below the PDF list sits a row of checkboxes. Each one you tick adds another tab, fed automatically by DCS. They mix freely with your own PDF tabs on the same board.

SourceWhat lands on the tab
DCS AircraftThe kneeboard pages DCS ships for the aircraft you are flying — switches by itself when you change slot.
DCS TheaterThe map's own kneeboard pages (airfield diagrams, charts).
DCS Mission (.miz)The kneeboard images the mission designer packed into the mission file.
DCS Briefing (rendered)The mission briefing, rendered into readable pages — optionally including the enemy threat list.
DCS Nearest AirfieldsLive text page: the three closest airfields with TACAN, ILS, runway, VOR and elevation.
DCS Moving MapA scrolling terrain map centred on your aircraft, with airfields and range rings.
WhiteboardA blank page you write on — see step 7.
MSFS and other sims The DCS sources need the DCS hook that the installer sets up, so they stay empty elsewhere. Everything else on this page — PDF tabs, paging, bookmarks, notes, shortcuts — works in any sim.
4

Paging, tab strip and placement

At the top of the panel you have < Prev / Next >, the page counter and a slider to jump straight to a page — handy while you set the board up at the desk. In flight you use the shortcuts from step 5 instead. Exit Document turns the mask back into a normal painting mask.

The page navigation row of the kneeboard panel: Prev and Next buttons, the page counter, a page slider and the Exit Document button.
The desk controls: page back / forward, the counter, a jump-to-page slider and Exit Document.

In VR the board draws its own tab strip across the top: the active tab is highlighted and shows "3 of 14" underneath, so you always know where you are. Long tab names are shortened with an ellipsis so they never bleed into each other. You can hide the strip with Show tab strip in VR if you want the maximum page area — the page then fills the whole board and you switch tabs blind, by shortcut.

The Show tab strip in VR checkbox at the bottom of the kneeboard panel.
Show tab strip in VR — ticked (default) the header with the tabs is drawn into the board; unticked you gain that space for the page.
The kneeboard tab strip as rendered into the mask, with the active tab highlighted and the page indicator below it.
The tab strip is drawn into the mask itself — this is exactly what you see in the headset. Active tab highlighted, page counter below the name.

Placement works like any other mask: drag it on the canvas, or use the [P/R] Pose fields and the move shortcuts. A kneeboard usually wants to sit low and slightly tilted, roughly where a real one sits on your thigh. Size it with Size (meters) — around 0.5 m wide is a good starting point, and the portrait aspect follows automatically.

5

Shortcuts for the cockpit

This is what turns the board into a real kneeboard: you never touch the desktop in flight. All of these live in Settings → Mask Shortcuts and can be re-bound to any key or HOTAS button — click Add next to the action and press the button you want.

Turning pages
Document: Next Page Ctrl + D One page forward in the active tab.
Document: Previous Page Ctrl + A One page back.
Switching tabs
Next Kneeboard Tab Ctrl + Alt + D Cycles to the next tab — and lands on the page you left it at.
Previous Kneeboard Tab Ctrl + Alt + A Cycles backwards.
Bookmarks and notes
Toggle Page Bookmark Ctrl + B Marks / unmarks the page you are looking at (step 6).
Whiteboard: Clear page Ctrl + Alt + X Wipes the notes page clean.
Whiteboard: Toggle eraser unbound by default Switches the pen between writing and erasing.
Moving map (DCS)
Moving Map: Zoom In unbound by default Zooms the map tab in — put it on a HOTAS hat for map work.
Moving Map: Zoom Out unbound by default Zooms out. The map can also auto-zoom with your speed.
The Mask Shortcuts dialog showing the kneeboard rows: next and previous tab, page bookmark, moving map zoom and whiteboard actions.
Settings → Mask Shortcuts — every action takes several bindings at once, so a key and a HOTAS button can do the same job (see the joystick binds in this list).
The one binding worth doing Put Next Kneeboard Tab and Document: Next Page on two HOTAS buttons. With those two you reach every page of every document you loaded — hands on the stick, eyes in the cockpit.
6

Bookmarks — your in-flight shortlist

A 30-page checklist has maybe four pages you actually need in the air. Bookmarks pull exactly those together.

  1. Page to a page you want quick access to.
  2. Press Toggle Page Bookmark (Ctrl + B).
  3. A small yellow corner appears on the tab, and a new Bookmarks tab shows up at the end of the strip.
  4. Repeat across any tabs — approach chart page 2, checklist page 7, aircraft data page 1. They all collect on that one Bookmarks tab.
  5. Press Ctrl + B again on a bookmarked page to remove it.
The tab strip after bookmarking a page: a yellow corner marks the tab and a Bookmarks tab has appeared.
Bookmarked: the yellow corner marks the tab that holds a bookmark, and the Bookmarks tab collects the pages from every tab.
Bookmarks are for the session They are deliberately not saved with the profile — a bookmark belongs to the flight you are on, not to the board forever. Set them during your briefing, use them in the air, start fresh next time.
7

Notes — write on your kneeboard

Tick Whiteboard (tablet / phone notes) and the board gets a blank white page as its own tab. This is where ATIS, clearances, headings, tanker frequencies and BDA go — handwritten, in VR, while you fly.

The kneeboard showing the blank Whiteboard notes page as an active tab.
The Notes tab: a clean page, right next to your charts.

You write on it with one of two input devices — a mouse does not work here, because you cannot see the desk in VR:

  • A graphics tablet (Wacom, Huion, XP-Pen …) via OpenTabletDriver. This is the setup that feels like a real kneeboard: the tablet lies on your leg, pen on tablet is pen on page, absolute position and all. Set it up under Settings → Tablet / Whiteboard, then calibrate the two corners once so the tablet area matches the page.
  • Your phone over Wi-Fi — open the page PassthroughForge serves, scan the QR code from the settings menu, and write with your finger or a stylus. No driver, no hardware, but less precise than a tablet.

Clear page (Ctrl + Alt + X) wipes it, and the eraser action turns the pen into a rubber — both bindable to your HOTAS.

Notes live for one session Like a grease pencil board, the page starts blank every time you launch PassthroughForge. It is a scratch pad, not a logbook.

There is a dedicated, much more detailed guide for the tablet side of this: Write on your VR kneeboard with a graphics tablet.

8

Tips & limits

  • Short tab names win. With five or more tabs the strip gets tight and long names are shortened with "…". "M02 Brief" reads better in the headset than "Rampagers M02 - Briefing".
  • Big scanned charts: PDFs are rendered at a fixed kneeboard resolution. Very dense A4 charts read better if you split them into portrait halves before importing.
  • Several boards. Nothing stops you from creating two kneeboard masks — charts on the left knee, checklist on the right. Each has its own tabs and its own page memory.
  • The tab strip is part of the mask. It is drawn into the page itself, which is why it also shows up on the desktop canvas — that is not a preview overlay, it is exactly what the headset gets.
  • Keep the PDFs where they are. The board references the files you picked; if you move or delete them, re-add the tab.
Something missing? This board grew almost entirely out of user requests — multiple PDFs, named tabs and per-tab page memory all came from pilots asking for them on Discord. If your workflow needs something the kneeboard can't do yet, that is exactly where to say it.