Any leather collar can be turned into a custom pet accessory. Just follow the same steps you would take a paint a custom leather shoe, by using the Leather Preparer and Deglazer to prepare the leather for painting. You will also want to tape off any metal pieces that you don't want to paint, like the buckle or name plate.
Applying thin coats and letting each coat dry is an important part of the process. If coats are too thick the paint won't be as pliable, which is important on leather that is going bend.
Paint your pets name in decorative font in a contrasting color to make sure it stands out.
Or you can paint any design for a collar as unique as your pet.