Say you want to create a custom color paper that matches an 3-D object or an element in a photo or image, and you want to add hand lettering to that colored paper. Here's a simple way to do it, even without a photo program (although that makes it easier).
1. Scan the item or part of the item that has the color you want. You don't have to scan the whole item--just the area with the right color. If that area is small, scan at high resolution--600 dpi or higher. If you are copying a color in a photo, if it is a printed photo, scan that portion of it with the color desired, and if it a digital photo, print it and scan the desired portion or if you have a photo program, crop the area containing the desired color. The crop does have to be any particular shape--any rectangle will do. Let's call this ""PaperColorFile".
2. Do your writing on plain white paper. Let dry completely.
3. Put the original written piece back into the printer and print the "PaperColorFile" over it, fitting the file to fit the paper size. If you doing a one-off, you're done. If you're doing many exact copies, either scan the original work, print it, and color the paper, or do further originals and color those. Remember, copies are never quite as good as originals (in my opinion).
Note carefully, that just printing the colored paper and then writing on it won't give as good results. Somehow, the colored ink changes the paper, making the writing bleed more. I'll show an example in the last photo.
If you have a photo program, you can improve your results of the PaperColorFile by resizing it larger, blur any imperfections out, and even fine tune the color, brightness, etc.
Here's an example--I wanted paper to match the car color, and even put a border around it.
1. original photo
2. Scanned small area of car, resized larger, blurred out imperfections/variations in color, toned down saturation a bit.
3. Pasted the original photo onto a 5 x 7 crop of the papercolor file (thus adding a border).
4. Example of original ink (iron gall) on white paper (bristol smooth), the first 3 1/2 lines then colored the paper. The S at the bottom was added after the color. See how the thins are not as thin and it is somewhat feathered? So ink first, then add color.