I know a lot of parents are leery of doing art projects at home for two reasons, one I addressed in my post process vs product... you don't have to be an artist to do kid art. The other is the mess.
A lot of people don't want to deal with the clean up of painting and other art projects. This is my solution to the issue. First thing I use is a vinyl table cloth, the cheap kind with the fuzzy backing. I can wash down anything that is spilled, but I really don't care if it get colored on. We even used it in the garage when we painted Colby's bookshelf. The boys know that they have to try to be neat, but if accident happen it's not a big deal. When I do really messy projects or ones that I'd like more contained I give them each an old cookie sheet. This is what I used when we did bubble art and car painting. The mess stays in the cookie sheet which is on the table cloth to ensure a clean space.
The last thing that I use is smocks on the boys and myself. The boys each have an old t-shirt that is about a size or two too big for them. Soon, I will give them each an old shirt of Richard's. When I taught kindergarten all my smocks in my classroom were old men's button down shirts. I would roll up the sleeves of a long sleeve button down shirt and have the children wear it backwards and just button one button on the back. Their whole outfit was covered up other than the bottom of their pants and shoes which when sitting doesn't really matter.
So, go to the dollar store, pick up a table cloth and some cookie sheets or trays. Go in your hubby's closet and find some old shirts (men's t-shirts work well too they just don't cover long sleeve shirts). Let them have fun!