Multi layer stencils

Multi-layered stencils take a bit more work, but the results are a much nicer looking image than a one color stencil. Here's one method for creating them.

First you start out like any other stencil.  You need a picture.  Paste it into a new image.  I try to keep mine 8.5 x 11 and at 300 dpi.  Custom sizes and lower resolutions should work fine too though.

Grayscale

Next you take the picture and make it black and white (grayscale).

Cleaned up background

Higher contrast image

Now adjust the brightness down and the contrast up.  You want to try and get a good balance of black, white, and grey at this stage.  You might want to go in and erase the background around your subject first.

Gaussian blur

The next step is to apply a blur.  Depending on your resolution, you'll want to adjust this up or down.  For 300 dpi, I apply a gaussian blur between 4 and 10 depending on what I'm working on.

Posterized (Black Layer)

Grey

Now, you need to posterize your image.  Make sure all of the colors are linked and set it to 2, 3, 4, or 5 (or more if you're so inclined).  You now have your basic stencil design.  Congratulations!  For this example, I will be using 3 colors.

This isn't going to be what we cut out and print though.  Duplicate your layer, this will be your Black layer.

To create the next layer, duplicate your Black layer and then select the black in your image.  Delete it.  This is now going to be your Grey layer.

White layer (and Black2)

Duplicate the Grey layer, select the dark grey color in your image.  Delete it.  This is now going to be your White layer.

Missing details?

Now you may have remaining details that you want in your stencil.  You'll need an additional black, and possibly an additional grey and white layer.  In my example I only need an extra black layer.  These extra layers need to be separate to be in our final stencil.  You will want to remove them in the white layer, since we are breaking them out separate we won't need them there.

Working with layers might be easier for you if you create an extra background layer and color it blue, green, or pink.  Just choose some light color different than the layers you are working on.  Also, if you're planning to use color in your stencil, you're going to have to create separate layers for each of those colors.  For example if your grey layer has two shapes that you want to be different colors, just duplicate the layer and then delete the parts from each that aren't going to be the other color.  If you're just using black/white/grey paint in your stencil like our example, you won't have to worry about that.

Black (filled)

Now you need to go through each layer and look for any islands.  No need to connect them with this process, but you will need to create another layer with your island and it will go on top of the layer surrounding it.  Pay attention to what order the layers will need to be applied.  These are your additional layers beyond the base layers (three in our example.)

Grey (filled)

Once you've identified how many actual layers you're going to need to do and separated them out, it's time to fill in your base layers.  By filling them in, you eliminate the need to cut intricate details on each layer as well as allow for overlap so there aren't any gaps if you don't line it up exactly when you go to paint.  Depending on how many layers you're doing, this will save you some time.  This isn't really an option for the final layers where we're focusing more on detail.  If you want to just do each color without any overlap, you can do it that way as well but it will take more time and require you to line up each layer accurately.

Black2

White (minus Black2)

Starting with the black layer, select the negative space (background).  Then invert your selection and use the eyedropper to select the black color.  Fill your selection with black.  Then select the Dark Grey layer and go through the same steps.  Select the negative space with the wand, invert your selection, use the eyedropper to grab the grey, and fill your selection.  Repeat this for each of your base layers.  In our example, we're only doing this on the first two layers.  For the white layer, we're going to remove the extra layer of black we want to lay on top of the grey and white.  Then we place it back in on the next layer.

Black

Now you have all of your layers.  In our example with three colors we ended up with four layers.  Your mileage may vary.  Go through them one by one and make sure everything looks right.  Look again for islands and look for the correct order they will be painted in.  Also look for any layers that have exact doubles of shapes.  If any of those exist, you only need to keep the one that will be the the top layer.

At this point, you can change all of the layers to black and then outline.  Print each layer individually.  You should clean up any little islands and edges at this point, making it much easier to cut.

Grey

Tape the paper to your cardboard or acetate or whatever medium you're using to cut your stencil from.  Make sure to line them all up the same.  This is going to be important when you go to paint them, you want all of them to line up with each other the right way or it isn't going to work.  Using the top and one side should be enough.  Just make sure to line up the same sides on all of them.

White

Black2

Cut them out like you would normally do.  It is a good idea to label them so you know which one is which.  When you have six stencils floating around for one picture, it can be easy to mix up which color and which order it should go in.  You might want to write on the side you will not be painting on if you are planning to use these more than once.

When you go to paint, make sure to line up the same two edges that you lined up when you cut them out.  A very important thing to keep in mind when painting is to let the paint dry in between applications.  If you lay your stencil down on wet paint, after you spray it and pull the stencil up it's going to smudge the previous layer or paint could even stick to the stencil and come off entirely.  If you just chill out between layers, you can avoid having to do a lot of touch up work or worse. Re-doing entire layers will make it an even longer process.  The more layers you have, the longer it will take to complete.

Painting

Painting your stencil is the final step.  You've done all the work to create your stencil and now it's time to put it somewhere for display.  Depending on your project, there are a couple of different application methods and an unlimited amount of surfaces for you to paint.  Generally, your surface needs to be generally smooth or your stencil is not going to turn out how you want it.

If you're painting your walls in your house with decorative stencils or quotes, you'll want to use a small paint roller (like a 3 inch trim roller) and a bucket of paint in a tray.  Using spray paint in your house or apartment is not something I would advise.

If you're working with canvas, cardboard, concrete, metal, wood, etc; you'll want to take it outside or in a well ventilated garage (or art studio) and use spray paint.  If you're outside, pay attention to the wind and get your can closer if there's a breeze.

Cover your mouth and nose and wear rubber gloves.  You might get some paint on your arms.

Mount your stencils to the surface being painted with a light mist of spray adhesive. Don't spray too much glue on it.  If you're doing multiple layers, I would advise not using adhesive after the first layer.

Use flat spray paint, don't use glossy spray paint.  Don’t let wet paint dry up on the stencil, you can lay it on some newspaper and wipe it off with a paper towel.  Be careful not to tear it.  One thing you can do is put one hand down on the stencil and peel it off with the other hand, being careful not to let the stencil slide and smudge your design. The best paint to buy is Montana Gold, but any rattle can of Krylon or Rustoleum will work as well.

If you’re doing multiple layers let each color dry before you start on the next one, otherwise you're going to smudge the wet layer. Depending on conditions, this could take 20 minutes or it could take an hour or longer.  It's important not to get impatient or you will wreck your picture and possibly have to re-do the entire design.  Find something to do while you wait for it to dry.  Each layer will take a bit longer because the paint underneath it will become wet as the layer on top of it is applied.

In general, I think it's better to underspray your designs.  Too much overspray or getting too thick with your spray paint doesn't look very good in my opinion.  You might have a different opinion and you're entitled to it.