Pre-compensate in Photoshop for printed color shift

[sammc007]

I'm having mugs made by a supplier using sublimation printing. The problem is that they are struggling to provide mugs with correct color. I realise that dye sublimation printing struggles to reproduce colours accurately, or with "pop", so I don't expect perfection. However, blues are coming out very grey, greens dull, and overall a dull coloration.

I don't have access to their printing process, ICC profiles etc. I thought that if I could take an image of the mug, and use Photoshop to make ajustments to get it back to maatch the original artwork, then I could perhaps use those adjustments in reverse to pre-compensate for the color shift in the production process. Hope that makes sense.

I guess I'm looking to create the equvalent of an ICC profile that I can bake into my original artwork before it goes to the supplier. If I export my adjustments to a color lookup table, and check the ICC option, can I do it that way?

Or is there another way altogether to achieve what I'm trying to do?

Any help appreciated.

[gener7]

If they do not want to share their profiles, offer to submit your design file as Adobe RGB and see if they or their software can do the conversion to their profile/printer.

[sammc007]

I've had a good dialog with them, it seems that the issue is they can't do a calibration in the same way you might calibrate a printer ink/paper combination using a standard array of color patches and a spectrophotometer to create a custom ICC Profile. They take PSD files using the Adobe RGB color space as their input to the process. I suspect that they have evolved some rough adjustment layers to apply before printing in an attempt to do what I'm also trying to do, though they haven't talked about that.

[gener7]

Ok. To be honest, I don't know enough to offer any other advice in this situation. There are others in the forum that may know, but we'll have to wait until they check in.

As an aside, I use a regular home/office printer and what I use is a standard brightness/contrast asjustment layer above the artwork to get my printer to render as close to the monitor as possible when printing color drawings. Brightness 40 and Contrast -40 as a starting point. You are brightening the image for print, and reducing the contrast to prevent blowouts. It's a "poor man's" substitute for a full color calibration setup.

[sammc007]

I appreciate you replying, and what I'm finding is that printing onto ceramic (in this case) isn't as smooth as using a lab for paper prints. I think it's going to be a trial and error approach along the lines you describe, tweaking colors and brightnesses etc. and seeing the results. Slow and expensive, which is why I'm holding out for a bit more automation via Photoshop. Problem is, my Photoshop experience is limited to specific areas, and this is outside those.

[Lumigraphics]

Take a photo of a color checker and tile it onto a mug graphic, with different adjustments to each copy. Have the vendor print this and use the copy/adjustments that best match your target.

[sammc007]

That was going to be my next step, with one difference. I'd import the photographed color checker mug into Lightroom Classic and use the color checker software to create a fake camera profile. I could then apply that profile to any images that are going to be put onto mugs.

[sammc007]

Though, if I followed your approach I could use the resulting layers to create a LUT that the company could use for all mug they make, not just mine.

[NB, colourmanagement]

It's really hard to match solid colour patches from a chart visually.

I'd try it with an image and layers.

I hope that you nave a calibrated screen to work on.

A test image is a good place to start, get it printed to a mug without visual adjustment - of course you'll need to resize to fit 

Go here and download the Adobe RGB testimage: https://www.colourmanagement.net/index.php/downloads_listing/

1: open the image you had printed to the mug, duplicate it alongside, so you have an original unadjusted image on-screen for visual reference later in step 4 below.

2: view the mug for comparison, in this example, the printed mug comes out dark and unsaturated

3: adjust one open Photoshop image so it matches the mug (viewed in daylight) using Photoshop's adjustment layers,

In this example the image on-screen needs to be darker and less saturated to match the mug 

Explainer - now you'll have a set of adjustment "initial mug matching" layers that include the correction needed,

but the adjustments are the opposite of what's needed.

i.e. Printed mug comes out dark and unsaturated - so, to print right - the image you send needs lightening and saturation boosting but your "initial mug matching" layers are darkening and desaturating it.

4: Leaving that initial set of adjustment layers active (maybe group them),

now make a second set of  "print adjustment" layers to go in the opposite direction

- i.e. back to the appearance you want [i.e. to match the unadjusted on-screen copy image) 

- e.g. lighter and more saturated, (you can take the adjustment values from the original layer set. Say your original pushed the middle "levels" slider 10 units darker, now you'd go 10 units the other way to compensate, same with saturation. )

5: Now deactivate the original ["initial mug matching"] set of adjustment layers and you'll see the image become far too light and too saturated. I'd save that test image with all layers intact so you can come back and do more adjustments to the layers, if needed, after a first printed test.

6: Now you can duplicate the layered image and, on the copy, delete the deactivated "initial mug matching" layers - now flatten, sharpen as needed and send off to print .

IF you succeed and get a mug you like, then you can drag that 2nd set of "print adjustment" layers to any image you want to make into a mug. Flatten and send off to be printed.

Alternatively, try find a dye sub printer who can match your originals using ICC profiles.

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

[sammc007]

Thank-you, this is a huge help. I'm waiting for a sample mug to come back, though unfortuantely it's printed with an image of the x-rite colorchecker patches. However, I'll try your process on it and see how it goes.

I appreciate you taking the effort to put together such a detailed respone.