I love stencils. I've been collecting them and using them in my work and in my classes for several years now. I've used them with paints and sprays (always make sure that your brush doesn't have a lot of water on it. You want it as dry as can be when you're stenciling.) I've used them with my watercolor crayons and pencils (scribble on waxed paper and use a slightly damp brush to pick up the color. Stipple the brush onto your surface.) My most favorite way to use them is with my pens and markers. I find it to be very meditative. Some days, I'll color them in completely, other days I'll outline them and leave as is or I'll color them in and outline them later. It all depends on my mood. I love using bits and pieces of a stencil, too. My favorites tend to be the smaller 6" ones that I can easily store in a ziploc bag and toss in my journal bag.
I like sturdy stencils that take a beating. The really thin, cheaply made stencils tend to irritate me more than anything.
Some of my most favorite companies to order from include:
Have I left your favorite stencil company off of the list?