Rub-Ons are some of my favorite things to use in my craft projects. They are super easy to use (even my kids can do it), and they are extremely versatile. Rub-ons can be used on anything from paper, to glassware, to wood, to plastic--pretty much anything with a somewhat smooth surface. Rub-ons generally come on a sheet with multiple designs and are backed by a protective page. You'll want to carefully trim around the image you would like to use, including the backing sheet. I like to check the placement on my project with the backing sheet on. Be sure to then remove the backing (talking from experience here--it's not a happy moment when you rub and then find you transferred the image not to your project but to the backing sheet). Using a popsicle stick rub over the entire image. Gently peel back the transfer sheet being sure the image has transferred. So easy, so fast, so cute. Try it, you'll like it!
Here are some things made better with rub-ons:
A card: use light colored rub-ons on dark paper for pop
River rocks: rub letters, words, or images onto smooth stones
Dishes and Glassware: use rub ons to personalize a plate, or add a little something extra to a bowl or vase
Ornaments: fill plain glass balls with crimped paper strips, add a rub-on and some ribbon for a quick decoration for any holiday.