The ones I'm making need the use of a laser cutter or other CNC equipment, but towards the end (step 4), I'll explain a couple of ways to do this by hand too.
access to CAD software
access to a laser cutter
3mm thick acrylic
On the last page of this instructable, there are some curriculum links - I've done this with my students, maybe you'll find somewhere to include it in a project with yours too.
Step 1: Design your buttons
Simple tends to work best!
So that the laser cutter can "read" the pictures, I've changed the colour of my cutting lines to red, and the engraving lines to black.
Step 2: Adding colour
You need to make sure that the dust from cutting has been wiped off first. Use a soft cloth or tissue to clean the buttons down, then put onto paper to paint. Cover the engraved parts in a reasonably thick layer of paint - you don't want it dripping off, but it has to work into all the little gaps. If possible, avoid getting too much paint into the sewing holes, if you can it'll save work later!
Leave the paint for 5 minutes or so, and then, using either a rag or tissue, wipe the excess paint off of the surface. You may need to dampen the cloth to take any dry residue off, but becareful not to push too hard, or you will start to pull the paint out of the engraving. Make sure you clean the sides and back too!
Step 3: Use!
Experiment with the patterning, the size, the shape, where the sewing holes are, the paints and colours used...... Have fun!
Move on to the next step for suggestions on ways to do this by hand........
Step 4: Buttons by hand
You can create a similar effect using pre-cut buttons. You want the slightly softer feeling ones - they're usually made of nylon or ABS. The shiny, pearlised ones generally do not work as well.
Using either a small chisel end, the point of a file/knife/graving tool, or, if possible, a carving tool in a dremel or similar, engrave your design by hand. I always draw out my idea in pencil first, and then go over the lines. If you are using the chisel/knife/file option, you may want to go over the lines 2 or 3 times to make them deep enough. Use a fine grade emery paper (or even a nail file!) over the top to smooth any rough edges off. You're now ready to paint!
Step 5: Curriculum stuff
At GCSE level, D&T students can recieve extra marks for making their own components rather than using purchased ones - make buttons to go on your textiles products. If you're doing product design instead, use the painting technique to add colour to laser etched designs - encourage students to experiment with paint effects, and the way this works on different materials, and with different depths of engraving.
You could do this as part of a KS3 syllabus, either as a button to go onto a textiles outcome, changed into a simple pendant for an RM/Graphics project, or even as a filler lesson to take up time at the end of term. Use it to teach CAD skills, and as a short and sweet introduction to using the laser cutter.