What you do is lightly draw squares with a pencil and then just color in the squares that you have drawn. This is a simple at home diy project. You decide what size you want the canvas to be then just set up your painting area wherever you want it to be.
Outside shower/bath why do I need an outdoor shower/bath? Because I have a metal smithing/garage/art studio and an outdoor garden which I like to keep my house clean when coming to & from these spots, so a shower would be nice, plus I have the space.