This technique will work well on aprons, costmetic purses, bags and tee-shirts as well as many other items of apparel. Once the paint is dry it can be heat set with an iron which will preserve the colours and the paint.
And it is so very easy. Let's go!
The most important thing to remember is NOT apply too much paint on at once otherwise it will 'leak' out through the stencil. The paint dries very quickly so if you want it darker, it is simply a matter of re applying the paint as many times as you like. Little and often is better in this instance.
So firstly I secure the stencil with some stencil tape and then put a small amount of paint on my mat. I ensure that I only have a small amount on my sponge and lightly sponge it through the stencil. I use a different sponge (or different side of the sponge) for each colour. Because this particular fabric is relatively porous the paint dries even more quickly and the different colours can be applied straight after each other.
In the case where I wanted the image to look as though it was 'dribbling' into each other, I just mixed a little of the paint colours on my sponge and then applied the different colours quickly to achieve this look.
I let the paint dry once I had completed my stencilling and then I ironed it the whole case, taking care to use a non-stick sheet between my case and the iron.
And hey presto! a pen and ink case for use very quickly.