Canvas is a fabric material that absorbs liquid well and is used for most painting projects. Canvas is capable of accepting almost any paint, ranging from acrylic to oil. If you are looking at creating your own sign or just want to place letters on the canvas, it is possible, either with a stencil or freehand. The process isn't far different from writing a sign in pen.
Apply a liberal amount of primer to the canvas. The primer places a nice, white coat on the canvas and ensures the paint layers stick to the canvas properly. Allow the canvas ample time to dry (several hours).
Place the stencil in position on the canvas. Make sure to hold it down to the canvas with either tape or some sort of grip. You don't want the stencil to move while you are painting it. If it does, just apply another coat of primer and start from the beginning.
Paint through the stencil you have attached to the canvas. Once complete, wait and allow it to dry. Leave the stencil on for the time being to give it time to dry.
Apply any additional coats to the stencil if you can still see the primer. Once you have applied the last coat, remove the stencil while it is till wet. This prevents the paint from pulling off when removing the stencil while it is dry (paint stuck to the canvas and the stencil pull off while you remove the stencil).