Wrap a rubber band around a few of these plastic broom straws and use them as a whisk for laying paints onto your size. Each bundle is enough to make 10 to 20 whisks, depending on how thick you make them. The more bristles in a whisk, the stiffer it will be.
Plastic whisks last for years and don’t break into pieces that then fall into your tray. They won’t get waterlogged and limp, you can wash them out and use them over and over.