Permanent Sprites

I'm building a Snapchat/ paintpot type app for a school project. 

I've created a basic stamp button where the user can pick from 3 characters and place them on the canvas when the user touches the canvas surface, in additional to a pencil element.

• The stamps aren't permanent and will move if the user clicks somewhere else on the canvas

• Only one stamp can exist at a time- no duplicates

Do you have any tips on how I can make the stamp function work?

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Every time the user drops a stamp, save the canvas and set that file where you saved it as the new background of your canvas. Now, there's a limitation in doing this because each time you save it, the compression algorithm decreases the quality of the image. Try it and see for yourself if it's ok for your project.

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