18 Overall polishing
I flatten all of the layers, and make some final touches to the image. The illustration still has many tiny flaws when I zoom in. So I set about clarifying the edges of the objects, fixing the mistakes and then adding some more details. I notice that the bubbles aren’t distinct compared to the character and background; for this reason I add a yellow glow around the bubbles so that they have a different colour compared with other objects in the illustration.