a client paid me a fair fee to be allowed to use an existing illustration I had done as a background image on their website.
Now they have contacted me to ask whether they could print the high-resolution version of that same illustration in a large-format reproduction to hang on their office wall.
Aside from any production / framing costs, how should I go about calculating a fair fee for the usage?
What are some considerations? Are there any pricing resources out there that could help determine a reasonable price?
(cross-posted to DeviantArt)