@kmmcrafts
I figure paper cost is less than $0.01 per page for me, but it is hard to figure out the cost of spray adhesive. I, too, factor the cost into my pricing. For me, fast and easy is the goal.
I try every method of attaching patterns that I run across. So far, I like attaching to the wood directly and removing the patterns with solvent the best. It's cheap, fast, and does not damage the wood, with the only downside I see is that I need to wait for the mineral spirits to evaporate. If the labels are removable with mineral sprits. Labels might wind up being my go-to method. Spray adhesive is messy, expensive, and getting hard to find.
I tried shelf liner. On a recent project, I used almost an entire roll. I did not like it. I found it difficult to apply due to the tendency to curl and a pain to cut, but the main thing I did not like was that it would sometimes leave a sticky residue on the wood that I had to remove with mineral spirits. If I have to clean it, I might as well stick the patterns on the wood and be done with it.