You may simply need a "custom" designed mask. There are companies that exist who do this for a living. It is very important to use a company that supplies mainly "custom designed" masking. There are some manufacturers that mainly supply "standard" masking who also dabble in custom "beware"...
Is it possible to vacuum-form teflon? or is there a sheet teflon that is heat shrinkable? I am looking for more cost effective ways to form teflon. Thank you, htfprich