To prevent using toxic spray paints, I have found a way to make mud stencils.
Design Your Stencil
First, you need to draw a stencil in the desired size or design it on your computer and print it. Though, ensure that you do not have islands (parts of a picture that will fall apart if you cut them in a round shape such as the middle of O.) If you are making use of text, then use a stencil font. However, if you are using a computer, you can print the stencil’s design according to your needs and desired results. If it is larger than 8×10, cut it into small pieces by using photoshop and print all the small pieces, or you can enlarge it at near local copy shops.
Tape your design in front of or behind the transparent mylar. Mylar is similar stuff like transparencies used in projectors. Moreover, you can also find the roll of mylar at art stores. Once you have done that, you can now use the X-acto knife to cut the mylar sheets’ main design.
Once you have cut the design, then you have to find or make the mud. I usually mix water and soil then beat it with a jerk. Though, you need to make sure that the mud and water are not watery. It should be dense, like peanut butter.
Tape the stencil to a spot wherever you want to print the design, such as on the sidewalks or walls. If some parts of the mylar roll out, then put some tape under it. Once it is properly placed, use the sponge to dab the mud on the respective stencil. Ensure that you do not put too much pressure on the sponge because it will bring out the muddy water and may lead it to sneak underneath the stencil.
Remove the tape from outside of the stencil and carefully remove the mylar so that it won’t ruin the design. At last, have fun with your non-hazardous mud stencil.