If you're new to Mod Podge, there's a chance that you'll get bubbles in your project. To avoid bubbles from the offset, try really hard to not shake the bottle at all. The agitation will cause bubbles. If you do shake the bottle, let it rest for a while to let the bubbles settle. If you lay down your comic book cutout and notice photos, you can use a tiny pin to pop the bubbles and let the air out. You can also, very carefully, go over your project with a rubber roller to try and get any bubbles and wrinkles out. You need to do this before your project is dry. Also, make sure that your rubber roller is completely clean before you do this or you'll be adding dust and dirt to the top of your coasters.