Thanks Parky, micro, lightly scoring the painted surface with the marker
helps a great deal, the paint stays away from the scoring and makes
stripes easier to manage.

I made this wing last night from the 1.13mm plate foam from Walmarts.
It's for the twin boom Sea Vixen and has a 12" wingspan and 3.2" chord.
The airfoil is 11mm thick at the root and I got the weight down to 4.1 grams.

Much closer to where a 14" x 2.5" wing could be made for stock AA's giving
you more lift.