3M 233+ Plus Masking Tape - industry standard
18mm can be used to tape over the Stringer on foam when spraying colour onto the blank.
233+ tape is perfect artworking your board. Use this tape to create sharp fine lines, stencils and cut outs on foam or filler/sanding coat.
For ideas and inspiration, there are many youtube videos on spraying,taping and artworking your board.