Painting with stencils allows you to reproduce a pattern or design over and over again, as many times as you like. These tips will help you get good results.
To achieve a straight line with a repeated stencil, such as one that runs down the length of a wall, you'll want to lay out a guide with a pencil and a long level, a chalk line put on with a line level or a projected one via a laser level. This will ensure that you won't end up with a design running slanted along the wall and will allow for repositioning your stencil with confidence.
Double-sided or another masking tape can work for adhering your stencil in place, though if you're working on a surface with a finish that could come off, you may wish to use something a little less permanent, such as low-tack painter's tape or spray-on stencil adhesive. Ensure all areas of the stencil are flat before you load your brush with paint.
Don't overload a brush with paint, as it'll seep under the edges of the stencil. Load the brush lightly, so that the ends of the bristles are covered evenly; wipe off any excess on a piece of paper or cloth.
You'll get better results by applying two thin coats rather than one thick one. Wait for the first to dry before applying the second.
Stenciling brushes are round with short, stiff bristles. Use them in a quick up-and-down movement to dab paint onto your stencil. This helps prevent paint from getting under the stencil's edges. A sponge or small roller works well too.
Start painting on the edges of the stencil, working from the edges inward, rather than from the center outward. Again this helps prevent paint from getting under the edges, as you're less likely to accidentally bump the brush against an edge.
To use more than one color in a stencil, use painter's tape to mask off areas of the stencil you don't want in a particular color.
If you're using various stencils together, first try each out on a piece of paper or cardboard. It's far easier to find out that something isn't working at this stage than when you're painting on your final surface—especially if that surface involves you on a ladder!
Old X-rays work well for creating your own stencils, so if you're unfortunate to need to have some taken, don't throw them away.
If you're doing a repeat design, wash your stencil regularly in warm water to keep the edges free of paint. If there's some paint globbed on an edge, you won't get a crisp edge to your painted design. Because paper stencils don't lend themselves to washing, acetate stencils are better for repeat designs. With a paper or card stencil, wipe off the excess paint, and then leave the stencil for a bit so the paint on it dries before using it again.
A stencil needs to be flat to be usable. To stop it from buckling, put it between two pieces of cardstock or cardboard and store it somewhere flat, such as in a book or large telephone directory.