u/Direct-Ask-3200

I'm a beginner with this technique and I have a question... Is it wrong, frowned upon, or inappropriate to alter a print using a painting technique, for example, watercolors? (More specifically, creating a watercolor background and then printing on top of it once the paper is dry). And if it's allowed, how would I sign it? Since it wouldn't be identical to the rest, I imagine it's not part of the same print run. I'm going to an auction at my art school and I had the idea of ​​using watercolor for the background of a print of a cathedral, but I'm afraid it might be considered inappropriate. Please help.