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philpem / printer-driver-ptouch

P-Touch PT-series and QL-series printer driver for Linux (under CUPS)
GNU General Public License v2.0
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No margins on QL printers! #1

Closed smurfix closed 4 years ago

smurfix commented 4 years ago

These label printers can print right to the edge. Setting a non-zero hardware margin, let alone one that wastes 10% of a label, does not make sense. The last row tends to get lost, thus I used a 1-point bottom margin.

andreas-gruenbacher commented 4 years ago

I'm not the maintainer of this repository, but I've been working on a new version under the original name (ptouch-driver), so I'd like to have this clarified. I'm pretty sure those printers can print right to the left and right edges as long as the print head is wide enough, but the paper isn't going to be perfectly aligned, so you'd have to print beyond the edges to get margin-free results. Neither this nor Brother's original driver supports that, at least as far as I can tell from the *.ppd files.

In the feed direction, continuous-length tape and die-cut labels are treated slightly differently, but either way results in a mandatory margin of 3 mm at the beginning and the end of each label for basically all labels. At least according to my testing on a QL-820NWB printer. (Some die-cut labels have slightly different margins, but none are even close to margin free.) When trying to go beyond those margins, I ended up with overly long continuous-length labels and wasted die-cut labels.

So the margins are set according to the raster command manuals for these printers for a reason. Please let me know if you think that a significant class of QL printers can be used reliably beyond their specification. Please describe which type of media is giving you the desired result, and include the entire raster command stream leading to that result so that we can reproduce.

Greetings to Nermberch.

philpem commented 4 years ago

I'd be cautious about risking print-head damage when over-printing. In a lot of thermal printers, the paper (or label in this case) acts like a heatsink for the head. Printing into air (which has effectively no heat sinking capability) can cause individual elements to overheat and burn out.

I'd be uncomfortable adding a zero-margin option for this reason -- and also for the reasons Andreas has mentioned.

andreas-gruenbacher commented 4 years ago

This would make the NegativePrint option dangerous as well. Neither the Windows nor the Linux versions of the Brother drivers have that option.

I've just tried out printing negative labels: the PT-P700 and PT-P900W printers only seem to enable the pins covered by the tape, resulting in very thin but noticeable margins. (The tapes on those printers are physically aligned at the center of the print head, so the print head extends on both sides.) The QL-820NWB does print beyond the edge of labels on the right, but a ~0.5mm margin remains on the left. This probably means that the print head doesn't extend right to the left edge of the label.