I am trying to print a photo onto basswood using sublimation. I then cut it to make a jigsaw. My problem is that the colour of the wood is "yellowing" the image once printed. I realise I could adjust the colours until I get a better result reprinting after each adjustment. I wondered if I could get closer quicker with less waste if I could scan the wood and use that to reduce the "yellowing" of the photo. If it's possible how would I do it.
Thanks. Shaun.
The interaction of colorants (inks) with a substrate is physically complex and therefor it is also hard to predict the impact of a substrate on color reproduction.
If this was for a large commercial project, you might want to fingerprint your process: print color-charts on wood, measure it with a spectrophotometer and use color profiling software to create a CMYK color profile for your process. You could use that ICC profile to either preview the effect (eg. In Photoshop) or even to automatically compensate (although that would be a stretch, considering that your process can probably not nproduce a decent white).
If this is for a hobby-project, (and assuming that you are using Photoshop) then I would fiddle with RGB correction curves until they visually match the samples that you already produced (to simulate the process). Then use those curves in an adjustment layer to preview your designs while you adapt them. (Don’t forget to hide that simulation adjustment layer before printing).
As others already said, mixing colored materials can create hard to predict results. The simplest case is that the printed colors and the wood do not affect each other at all, the yellowing is only the product of filtering effects:
In RGB color terms some B is missing, so you could in theory compensate by increasing it in the original photo. You seemingly have already thought this and you only search some confirmation and hints how to make it in practice.
Unfortunately there can be areas where the B is already in its maximum, for ex. all white areas, so you can only increase the percentage of B and you should do it by reducing red and green. This will reduce the available contrast and your image will look underexposed.
We can try what you could get at best with this idea:
On the top I have an image of wood (a random capture from a webshop inventory, unfortunately not the same as your wood). It has got blending mode Multiply to simulate filtering. In the bottom there's a random sports news photo. The result is heavily yellow as expected. It has also poor contrast, because the wood removes tens of percents of the light. White paper would take less. The photo is, of course, at first adjusted to a printable color range by converting it to CMYK with relative colorimetric conversion intent and then back to RGB.
As said by others a compensating adjustment layer can be used. It's inserted in the next image:
Red and green are reduced, blue is the default. The resulted color is nearly neutral in the lightest areas of the wood texture, but the contrast is poor. This very likely cannot be accepted when one tries to make attractive toys. The contrast would be better if you can accept white areas to become the same as the wood. Then you can increase blue.
Just for a comparison: The right half of the next image has the original (after making it possible in CMYK) photo colors and the left half has the assumed blueish precompensation which is made by reducing red and green. The wood layer is closed.
My suggestion: Try to find a way to make the wood closer to white - a white underpaint or chemical treatment. Unfortunately I cannot tell a working method which will integrate well to your workflow and cost expectations and doesn't interfere with the printing. People who print on canvas have the same problem, so it's possible to get some hints from there.
