gutenprint-cardtray

A small patch to Gutenprint's Canon driver that lets Linux print onto inkjet PVC ID cards (CR80, 85.6 × 54 mm) using a PVC card tray in the printer's CD/DVD slot — tested on a Canon PIXMA MX922 with the Brainstorm ID "Canon J" card tray.

Why

Canon's disc-capable PIXMAs can print on anything that rides in the disc tray, and third-party card trays exploit that to hold two CR80 cards. On Windows and macOS the Canon driver offers a "Disc Tray J" paper size and prints the whole tray face. On Linux:

• Canon's own Linux driver (cnijfilter 3.90) has no tray selector at all — cassette only.
• Gutenprint does know these printers and the CD tray (InputSlot=CD, disc media types, disc page sizes), but it assumes the thing in the tray is a disc: it masks everything outside a 120 mm circle (and inside the hub) and only allows a ±15 pt (5 mm) position nudge.

Two CR80 cards side by side form a 115 × 86 mm block whose corners sit 72 mm from the centre — outside the 60 mm disc radius — so the card corners come out blank, and 5 mm isn't enough to move the block onto the slots. The only Linux driver that handled this was a paid one.

What the patch does

Twenty-four hunks across src/main/print-canon.c, src/main/canon-printers.h and src/xml/papers/standard.xml:

1. StpCDNoMask — a new boolean option, "CD tray: no disc mask". When true the driver skips the circular disc/hub mask and dithers the whole square CD page (120 × 120 mm for CD5Inch). It is only offered alongside the CD input slot and defaults to off, so disc printing is unchanged.

2. StpCDXAdjustment / StpCDYAdjustment bounds widened from ±15 pt to ±120 pt (±42 mm) so the printed block can be walked onto the physical card slots.

3. MX920 disc mode — Gutenprint only sends the disc-mode command ESC (r 0x68 for a hard-coded list of older models. The MX920 entry's own comment says it needs it, but it wasn't on the list and lacked the CANON_CAP_rr capability that gates the code path, so the printer accepted disc jobs and silently discarded them (IPP job "completed, 0 impressions"). The patch adds both.

4. MX920 tray J page geometry — Gutenprint routed the MX920's CD jobs to the legacy 8-byte ESC (p page command; the printer scans the tray and ejects it unprinted. The MX920 now takes the same path as the iP7200 (extended 46-byte ESC (p with the tray-J border adjustments), which is what Canon's own Windows driver sends — verified against a captured Canon job (ESC (P, ESC (l, ESC (c, ESC (r byte-identical).

5. PageSize=TrayJ — a new page: the whole disc-tray face, 5.16 × 10.01 in, fed from the CD slot with ordinary margins and no disc mask or disc centring. It is the page Brainstorm ID's templates describe, so their PDFs print unchanged: lp -o InputSlot=CD -o PageSize=TrayJ -o MediaType=DiscCompat -o Resolution=606x600dpi template.pdf. Offered for the MX920 and iP7200 (tray J models). On the MX920 every header command in the job is byte-identical to Canon's own Windows driver (captured tray-J job): ESC (p with page 3071×5311, printable 2911×5122, origin 80,70 at 600 dpi, and the legacy medium fields 292×513.

   Where the cards land (the part that cost a week): Canon's tray-J medium is 8.85 in long, Brainstorm's template page is 10.01 in. On Windows the PDF viewer centres the page on the medium, so the template's card positions assume the page top sits 0.58 in above the medium's top edge. Gutenprint anchors the page top at the medium's top edge and printed every card 14.5 mm too far toward the trailing edge, no matter what the PDF or the paper advance said. The patch therefore sends no initial paper advance for TrayJ on the MX920: with the page's 50.8 pt top margin that reproduces the centred placement to within 0.01 in. Horizontally, raster column 0 always sits at the ESC (p origin, so the page's left margin is the lever: TrayJ uses 12.84 pt (10 pt + a measured 1 mm), and the driver lets that paper margin through its 10 pt minimum-border clamp. Verified on 2026-09-16: Brainstorm's unmodified template prints its card outlines on the card edges.

Everything else — disc media codes, resolution modes — is stock Gutenprint.

Install (Ubuntu / Debian)

# enable deb-src for your Ubuntu archive first (deb822: "Types: deb deb-src"), then:
./build.sh

build.sh fetches the distro source package, applies the patch, bumps the version to …+cardtray24, builds with dpkg-buildpackage, installs libgutenprint-common libgutenprint9 printer-driver-gutenprint, pins them with apt-mark hold, and regenerates the PPDs of existing Gutenprint queues. Prebuilt .debs for Ubuntu 26.04 (…+cardtray24) are attached to the GitHub release.

Why the version bump matters (learned the hard way, 2026-09-15): a patched build that keeps the stock version string is one unattended-upgrades run away from being replaced by the archive's identical-version package — and dpkg -i silently clears an existing apt-mark hold, so "I held it" is not enough. With the +cardtrayN suffix the archive is never a candidate, and the hold is belt-and-braces.

The Canon driver is a loadable module; grep -a -c CDNoMask /usr/lib/*/gutenprint/5.3/modules/print-canon.so prints 1 when the patched build is live.

Use

Add the printer with the Gutenprint PPD (it does not show in lpinfo -m; use the driver URI directly):

sudo lpadmin -p canon-mx922 -E -v lpd://<printer-ip>/lp -m 'gutenprint.5.3://bjc-PIXMA-MX922/expert'

Use LPD as the transport. On the MX922 both BJNP and IPP dropped multi-megabyte tray jobs mid-print: the printer ingests a streamed job slowly, prints band by band, and eventually times out the connection (IPP: "Unable to add document to print job", a third of the way down the cards). Over LPD the spooled file lands in seconds and the head runs at full speed. Small jobs (card outlines) work over any transport, which hides the problem until the first full-bleed page.

Print a 5.16 × 10.01 in page laid out like Brainstorm ID's Canon-J template (two 2.125 × 3.375 in cards, top edges 3.67 in from the page top, left edges at 0.325 in and 2.745 in) — their own template PDFs work as-is:

lp -d canon-mx922 -o InputSlot=CD -o PageSize=TrayJ -o MediaType=DiscCompat \
   -o Resolution=606x600dpi -o StpCDNoMask=True -o fit-to-page=false cards.pdf

Print with the tray out; the printer stops and asks for it, and gives up after a few minutes if nobody inserts it (the job then stays queued and retries when you press OK). Cards must be inkjet-printable PVC — plain glossy PVC won't hold ink. The older PageSize=CD5Inch route (120 × 120 mm page, disc mask off, StpCDXAdjustment/StpCDYAdjustment to walk the block onto the slots) still works for printers without a tray-J page.

A generator that lays out CR80 label artwork on this page lives in the author's labels tooling; any PDF of the right size works.

Compatibility

Built and tested against gutenprint 5.3.4.20220624T01008808d602-4ubuntu2 (Ubuntu 26.04). The touched code is unchanged in Gutenprint git master, so the patch should apply to 5.3.x generally. Any Canon model Gutenprint lists with a CD tray should benefit; only the MX922 has been exercised.

Upstream

Not upstreamed yet. A cleaner shape for Gutenprint proper is probably a CDMask string option (Disc / None) instead of a boolean, and a per-model default for the adjustment range.

Licence

Gutenprint is GPL-2.0-or-later; this patch is a derivative work under the same licence (see LICENSE).