Painting on cardboard or boxes as a replacement for regular canvas can really give your painting a whole new dimension. Although this type of material can be somewhat problematic in some ways, it does provide a cheap and eco-friendly way of painting.
Before you can begin painting on cardboard it is important that you coat it with one or two layers of gesso. The gesso will help to support the delicate cardboard and prevent it from soaking up too much water, which can cause it to collapse. I prefer to always use the cardboard with two layers, and I usually wait for a couple of hours between the layering.
Once the cardboard canvas is sufficiently dry it is time to bring out the acrylics and the brushes! Now painting on cardboard is A LOT different from painting on regular fabric canvas. The two biggest differences are that the cardboard easily absorbs the paint, so you must be quick and be prepared to use more paint from what you are used to.
The second difference is the structure of the cardboard itself. All boxes or sheets of cardboard have a linear structure which will make or break your painting. However, the structures on the cardboard canvas will make the painting look more alive. It works almost like a regular impasto and gives the painting an interesting 3D effect.
When painting with acrylics on cardboard there really are limits as to what works and what doesn’t. I have previously made both portraits and surrealistic paintings on cardboard sheets with good results. The most important factor in my opinion is to work with the structure of the cardboard and not fight it.
If you want to apply a glaze or two to your painting then you should be careful with the amount of water that you use. As mentioned, this medium doesn’t really work all that well with water, so be patient and allow for the glazed layers to dry up properly before moving on with the painting.
Using cardboard boxes can also be very interesting and offers you a 3 dimensional structure to paint on. I have not had the best results myself, but I know of other artists who have made some interesting art pieces this way. For my own part, painting on entire boxes has mostly served as cars, planes and pirate ships for my kids.
One last tip is to not use water with your acrylics, but purely paint impasto/dry brush on cardboard. Again, this is important to avoid the cardboard from collapsing.
I hope you found the information useful and that it might be added to your arsenal of acrylic painting techniques.
I have attached a short easy to follow video-guide on how you can start painting on cardboard.