Most stencils need to have at least a few bridges. Without bridges, the islands in the stencil just fall out when you cut them. And when you paint a stencil with bridges, there are going to be gaps in the paint where the bridges were.

You can address this by eliminating the bridges in the first place, or by filling in the gaps created by the bridges after painting.
We cover the first topic, eliminating as many unnecessary bridges as you can, in another post.
The second method is the reason for this post. Some stencils just have a lot of bridges, and there’s no way to get rid of all the visible ones. For those stencils, you need to have a way to fill in the bridges so that the stencil looks clean.
Freehand
Of course, you can use a can of paint and a thin cap and cover the bridges freehand. This can get really tricky when the bridges are short and there are a lot of them. With freehand, you’re going to need a very clean, skinny cap (what is a skinny cap?), and a very light touch to get a good result. As soon as you finish painting each layer, just put your skinny cap on your can and get in as close and accurate and quick as you can to clean up those areas where the bridges show through. If you have just a few long bridges in a big dark area, then those are easy to cover.
Using a Secondary Stencil
Sometimes your bridges are right next to areas that you want to keep clean at all costs: like a big dark area next to an area of hot pink with detailed edges. You really don’t want your overspray to touch that hot pink area. You want a controlled mask to fill in those bridges.
With a secondary stencil, you basically use a stencil to fill back in just the areas under the bridges. So the stencil just allows the paint to cover the areas where the bridges were.
The secondary stencil is illustrated in the video.

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The main advantage to using a secondary stencil to fill in the bridges is that you can quickly complete a clean, dark layer and substantially improve the look of the stencil overall. We’ll cover construction of the secondary stencil in a future post, but to get you started, you really just have to paint the primary stencil and lay a clean piece of translucent material over it, and mark the places you want to cover up. Then cut it out.
There are a few drawbacks, and an additional consideration:
- You have to register (line up) the layer really well to make sure you don’t add black stripes to your surface in the wrong place.
- You use more paint because you’re basically painting an extra layer
- You have to keep track of the stencils, and pair them with the right primary layer
- You can’t use partial coverage (or feathering) on the primary layer when you’re going to ‘cover up’ with the secondary layer
On balance, I find that if my darkest layer has a bunch of short, annoying bridges in it then it’s better to use a secondary stencil to fill the bridges. On lighter layers, it either doesn’t bother me as much to see some bridges, or they’re easier to fill using freehand techniques.