What to do with your digital "negatives"

You know that sheet of tiny "proof" pictures that comes with your order of digital prints?
I usually toss those along with the envelope.
Rewind a few months back; I had requested a paint sample book from a website (the name escapes me at the moment).
I cut the photos leaving most of then with
a small white border.
Then, I used double sided sticky tape to attach them to coordinating paint swatches.
This was the result....