Fumage is a way of making pictures using smoke! Imagine you have a special paper, like the ones you use to draw pictures with your crayons. Instead of using crayons or markers, you hold the paper over some smoke (like the smoke that comes out of a candle). As the smoke rises up onto the paper, it leaves behind some colors and patterns.
Sometimes people like to use special tools called "fumers" to control the smoke and make it go where they want it to go. These tools have a tiny hole in them, kind of like a straw, that helps to direct the smoke.
Once the smoke pictures are done, they are usually coated with a special kind of glue to keep the colors and patterns from rubbing off. Some people like to display the pictures like pieces of art, while others might use them to decorate things like scrapbooks or handmade cards.
So, think of fumage like making pictures with smoke instead of crayons or markers. Cool, huh?