This is one that I have wanted to do for a long time. So long that the original post has been removed from Modern Dog Magazine. (I guess Modern Dogs aren't doing this any more.) You could search on Pinterest, but when I did that I came up with the original I pinned that no longer exists, and a bunch of people who pinned pictures and not directions. Still, it's not rocket science.
I did require the assistance of my man for this craft but that's because the dog is who she is. I used a brayer to spread black (nontoxic) acrylic paint onto the dog's paw. Then we made her stand on a piece of paper. (The trainer was right, that "stand" command came in handy!) I had a soapy bath ready for her paw so that we could wash the paint off immediately (to avoid the dog licking it off). We also chose to do this in the kitchen with tile that could be washed. (I may have done it outside if night hadn't fallen.) Also, dried chicken--her favorite treat--was applied liberally.
I didn't use ink like many others because 1) I only have Stazon which... stays on--not good for my floor or the dog and 2) I don't think Stazon cleaner is nontoxic, even if the ink is. Ultimately the paint comes off with soap and water so it won.
I'm happy to answer any questions you may have about this process, because I think this is a super special way to remember your favorite pooch!