Q&A for How to Decoupage on Glass

Yes, you can. The trick is to use only thin layers of glue. If you're putting a photo on the jar and know you'll need to move it around, put a layer of Mod Podge on the glass and the back of the photo. This will prevent the paper from tearing as you slide it around. The other important thing is to make sure the pictures and jar are totally dry before applying a second coat of Mod Podge. Otherwise, the pictures will get too wet and tear.

Here is a great article to help you get started: How to Make Stained Glass .

Oven curing is not required but is very useful between coats, or if you don't have an ideal curing environment. According to Patti Elhoff, author of Upcycle with Decoupage, as well as in my experience, most decoupage glues will tolerate 175 degrees F. Place in a cold oven; once it reaches 175ºF, turn off the oven. Keep the oven door closed for 1 hour. This definitely works with paper and napkins. I would hesitate to use for photos or anything plastic.

The shiny spots are most likely drops of sealant. It can be hard to avoid drips or spots of sealant getting on non decoupage areas. Use masking tape around the work area to reduce splash over. If is accidental transfer from handling, then add plastic wrap around the non decoupage area. Use masking tape to hold the edges in place. Spots can be gently scraped off then wiped off with alcohol or manufacturer recommended solvent.