Photoshop | My printer has started printing slightly oversize

[Eric the gray]

I've been working over a print on A2 sized paper (594mm x 220mm) and have made a number of trial prints over the last few days.  I am printing on an Epson SureColor P800 set to marginless mode.  The image size is set to 594 x 220 and I have been filling full width of the paper.  However the margins on my last print yesterday were smaller than expected and I have found that the image (landscape) has increased in height by 10mm and in width by 12.5mm. I have done nothing which might hasv brought this about. By printing from CAD files at 1:1 scale I have verified that the printer's scaling is still extremely accurate. Windows 11 Pro is 23H2 was updated to OS Build 22631-3672 on 19 April 2024. Photoshop has been updated almost daily and I believe the last update was yesterday (7 June 2024). I have no details of the version. The printer driver and firmware has not been updated for months. I strongly suspect the problem has something to do with PhotoShop and I would be grateful for suggestions as to what might be happening. In the meantime I will have to rescale ay prints but that is not a long term solution.

[Eric the gray]

Just to add to the above: When printing from CAD the print size errors are no more than +0.12%. When printing from Photoshop the error is +3%, which is significant on a 420mm long A2 sheet. An Internet search found a number of people experiencing the same or similar problems, two of whom had cured their problem by reverting to an earlier version of Photoshop. One person  was able to reinstall the then current (previously troublesome) version and found that the printer size error had vanished. I have tried that with Photoshop versions 25.7, 25.9, 25.9.1 and the problem follows them slavishly. At one stage when uninstalling 25.9 I did not trust the Photoshop uninstaller to clean everything out and I used Revo uninstaller to dig deep. Usual oversized result. My test print for this was a discarded trial print with a 20mm plain margin. My test image was a plain sheet with 400 x 574 rectangle framed with a 5 pixel wide line. This should have printed down the centre of the margin on the print, but it didn't. I used a different colour for each trial run and I now have a misplaced muddy brown rectangular frame on my test sheet with the line no more than 6 pixels wide (printed at 1440 dpi). The printer seems to extremely consistent and precise in its operation. The error seems to be somewhere in the print train from Photoshop to the printer. Does this ring a bell with anyone?

[davescm · Accepted solution]

'I am printing on an Epson SureColor P800 set to marginless mode'

In the Epson print driver, when you select Borderless printing is your Expansion set to 'Auto Expand' or 'Retain Size'?

The screenshot below is for an Epson SC-P5000 but the options should be similar

Dave

[NB, colourmanagement net]

@Eric the gray I too have found that printing edge to edge (borderless) from Photoshop on an Epson printer adds a little by slightly enlarging the image. Could that be it? @davescm provides more detail on that. 

I hope this helps neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right' google me "neil barstow colourmanagement" for lots of free articles on colour management Help others by clicking "Correct Answer" if the question is answered. Found the answer elsewhere? Share it here. "Upvote" is for useful posts.

[Eric the gray]

Greta minds think alike - and I wish mine had thought faster. Both 'davescm' and 'NB, colourmanagement". Have come up with the correct answer. I found this when I was in the process of announcing my discovery that turning off Borderless solved my problem. But apart from that I never dreamed that 'Expansion' had anything to do with this. I've been using Photoshop with Epson printers for years and never dreamt that 'Borderless' did anything but remove an inhibition on printing to the very edge of the sheet. I have run another test this morning and found that the size error is less than 1mm over a length of 594mm. In fact, whetheer or not there is any error appears to be dependent on the thickness of the sheet. I must now go an explore 'Expansion'. Thank you both very much.

[Conrad C]

…never dreamt that 'Borderless' did anything but remove an inhibition on printing to the very edge of the sheet.

By @Eric the gray

The technical problem with “borderless” printing, regardless of brand or model, is this: How do you guarantee edge to edge printing?

In traditional press-based printing, edge-to-edge printing is done by setting up the document with a “bleed” (the image size includes an outer buffer area beyond the final paper size and the design is extended into that), it is printed on a larger sheet than the final required paper size, and then after printing, the bleed is trimmed with a blade so that there is no gap between image and paper edge and it’s the correct size and scale. It looks great.

The problem with doing borderless on affordable inkjet printers is the precision of the paper transport. At the low price point these things are sold at (and yes, I mean “low” even for $1200 printers because a press can cost a million dollars), there is no option to trim all edges, and sufficiently precise paper transport cannot be guaranteed at this price point. If you try to say “Print me an A2 print on an A2 sheet, edge to edge, no scaling,” there is a high chance the paper transport will off by juuuuuust slightly enough that there will be a paper-colored hairline on one side or the other.

So on affordable inkjet printers, the only reliable way to achieve “borderless” prints is to slightly enlarge or “expand” (scale) the image, resulting in overspray. That can be slightly messy at the bottom of the printer…but you do get edge-to-edge ink coverage.

That works great for photos, because nobody notices if a photo got scaled up by 1%. But for a document that must be exactly to scale, a 1% expansion is a disaster. This goes back to these devices being designed and marketed as photo printers, not technical plotters.

A workaround is to do what the press people do: Design with a bleed, turn on trim marks, print on a larger paper size with “Borderless” disabled (no expansion, to maintain the scale), and then after printing, trim your smaller edge-to-edge image from the larger sheet by cutting along the trim marks. Of course, this works only if you own a printer that can feed a paper size that is larger than your final paper size.

[NB, colourmanagement net]

@Conrad C That's a nice explanation of the limitations of edge-to-edge or borderless inkjet print.

I hope this helps
neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management
Help others by clicking "Correct Answer" if the question is answered.
Found the answer elsewhere? Share it here. "Upvote" is for useful posts.

[NB, colourmanagement net]

@Eric the gray appreciate your thanks, please mark the answer you like as correct so others can see the solution.

I hope this helps
neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management
Help others by clicking "Correct Answer" if the question is answered.
Found the answer elsewhere? Share it here. "Upvote" is for useful posts.