This doesn’t need to be a deep clean, just make sure it’s clear of any debris. If you purchased a rougher board, you may want to sand it and remove any dust from that.
Apply the Joint Compound
You’ll want to use the joint knife to completely cover the board in joint compound, but here’s where a little skill and practice come into play. After covering an area in joint compound, run the joint knife gently over the surface in alternate arching motions.
You want to create ripples and light lines that run in different directions to create movement and depth. If you don’t like how it looks, just keep trying different amounts of pressure and adding more joint compound if necessary.
Once you like the texture, allow the joint compound to dry completely. This could take several hours to overnight.
Apply the Paint
Once your joint compound is dry, pour several pools of each different paint on the board. Using the rectangular kitchen sponge, spread out the paint, mixing and swirling so that it isn’t just one color in any one space.
You also don’t want to overmix because this would create one color as well. I like to use the sponge to spread out the colors, then dab it lightly to soften the look of the paint so it doesn’t have a “wiped” look
You could actually skip the joint compound and use the sponge to paint directly on the wood board, which you can see on the board in the photo below.
You could also be done at this point if you’re happy with how the board looks. I decided to go for a little more depth, because the texture in the joint compound is just too good to leave untouched!
Apply an Extra Layer of White
Once your paint layer is completely dry, use the sponge brush or another clean sponge to grab a little bit of white or your lighter color mixed with white. You want this to be a very small amount of paint. If you’re familiar with dry brushing, that’s what we’re going for!
Lightly brush this light colored paint across the texture of the joint compound. You want the light paint to be on top while the darker colors come through in the cracks underneath. You can make this as pronounced as you want or not. I decided to make one half of my large board more white and textured, and leave the other a little flatter.
Once this layer dries, you can move on to the other side! I know some people apply a matte finishing spray to protect the surface, but I’ve never had a problem wiping food and stains off my board. I’ve also never been able to actually FIND matte finishing spray (because I seriously know nothing about hardware stores), so I think you’re ok with or without it!