To create stencils for painting or inking, you will need to separate the colours of your design. Each colour needs to be on its own sheet. A graphics program can separate the colour onto different layers and it does not have to be a pricey commercial application. The freeware program GIMP is more than up to the job.
Start GIMP. Select "File" from the menu and click "Open." In the dialogue that appears, locate and open your design image.
Click the "Select by Color" tool from the toolbar. In the tool options, turn off "Antialiasing" and "Select Transparent Areas." Set the "Threshold" to 55.
Use the tool to click on one of the colours in your design. This will select all of that colour in the image, whether the areas are connected or not. Use the "Copy" and "Paste Into" functions under "Edit" to move this colour to a new layer. The new layer is automatically created when you paste. Repeat this to place each colour on its own layer.
Select and delete the original bottom layer. Then click on the eye icons next to all of the layers but the bottom one. Print this layer. Then hide this layer, unhide the next layer and print it. Continue this process to print all the layers separately. Now cut out the coloured part of each printed page and your series of stencils are complete.