We're running a T shirt decorating workshop for beginners at DoES Liverpool's maker space. Mainly we'll be using our vinyl cutter to cut out iron-on vinyl, but I thought it might be nice if people could use some of our other equipment as well - this T shirt uses interchangeable laser-cut letters.

Step 1: Tools and Materials

Materials

1. T shirt

2. Small pieces of 3mm Perspex or plywood sheet

3. Approx. 600mm of 5mm sew-on Velcro – you only need the “Loop” (fluffy) side which you can often buy separately

4. Approx. 300mm of 5mm heavy-duty stick-on Velcro, depending on the number of letters – you only need the “Hook” side

5. Sewing thread

Tools

1. Sewing machine

2. Laser cutter

3. Computer with 2D vector graphics software such as Inkscape

4. Scissors

5. Pins or glue

Step 2: Make the Letters

Think up a few slogans for your T shirt and use a 2D vector graphics program, e.g. Inkscape or Illustrator, to produce a cutting file for your laser cutter. Simple outlines, such as trains or zoo animals, could look good too.
Cut out the letters from 3mm Perspex or plywood sheet (Untreated MDF isn’t suitable as the surface fibres come off and make it difficult to stick to the Velcro – it might work if you prime it first).
If you don’t have access to a laser cutter, you could use magnetic fridge letters.

Step 3: Stick Velcro to Your Letters

Cut strips from the hook side of the stick-on Velcro to the width of your letters – in my case they needed to be 2 hooks wide.
Cut the strips to the right length and stick them on to the back of the letters.

Step 4: Sew Velcro to Your T Shirt

Cut 2 strips from the loop (fluffy) side of the sew-on Velcro to the required width (you probably don’t need to go all the way to the side seams as you won’t be able to see the letters there and it tends to make the T shirt stick out at the sides).
Place the T shirt on a flat surface and position Velcro strips where desired. Secure to the top layer of the T shirt with pins or glue, and sew round the edges to secure.