mousepad
acrylic paint
stencil brush or a stiff brush
acrylic sealer
stiff plastic to make a stencil (the plastic that bacon lays on works great)
tape
X-Acto knife
Celtic design to trace
Paint the mousepad to a solid color if needed; allow to dry
Trace the Celtic design onto the stiff plastic
Cut out the stencil with the X-Acto knife
Place the stencil in the desired location over the mousepad
Tape the stencil in place
Using up and down stabbing motions, stencil the design. Allow to dry
Spray or paint the acrylic sealer over the design. Allow to dry before use.