How to fix decoupage when there are air bubbles after it dries?

Depending on the size of the bubbles, I've opened large ones with a fine pair of scissors or sharp exacto/razor blade. Then apply a tiny bit of the decoupage glue with a toothpick or fine paint brush and carefully push the bubble down. Use a pin to poke tiny bubbles and then apply another coat over the entire piece. I use a wallpaper brayer sometimes when everything is wet to get bubbles out as well. Hope this helps. Happy holidays!

Thank you so much.

If you do a lot of decoupage you should own a brayer. Or you can use a credit card and carefully pull it over your element.

Ive done what Jan does. Works great.