Islands are an incredibly common problem for new stencilers. You can’t just take any black and white image and use it as a stencil. An island is a space in a stencil that is surrounded by a part that needs to be cut out. For example:
The easiest solution to this problem is to just get rid of the islands as seen here:
While this method makes the whole process of cutting the stencil out and painting it a hell of a lot quicker and easier, sometimes you want or need to keep islands. For example, in the scissor stencil, there is really no way of getting rid of the islands without the image looking awkward.
A second solution to the problem is cutting out the islands separately, keeping them, and adhering them to your canvas along with the stencil itself. This works when you are using spray adhesive, freezer paper, contact paper, or another form of adhesive.
Although this works, it can get very confusing; it is easy to lose the islands. You might forget which islands go where, and you might not know how to place the islands down.
The most effective way to deal with islands is using a method known as bridging.
A bridge is a small connection between the outside white space and the island. When you cut out the stencil, treat the bridge as if it is part of the space you keep intact with the rest of the stencil.
In this particular stencil, you would treat the bridge (red) as if it were white when cutting it out. After you paint and remove the stencil, go back with a small brush and fill in the bridge with the color paint you used for the stencil.