First test scribing: Each batch of Vipers is different- the no cockpit ones made in America have a more solid polystyrene that is easier to scribe- these are the 30th anniversary ones
with cockpits, made in China, and this polystyrene is a bit softer & more prone to 'flare' accumulating on the edges of the cut...
I scribe not with my scribing tool (not happy with the 'V' shape it cuts), but with an exacto knife with a broken tip- backwards. Straight edges with a metal ruler as a guide, curved surfaces with the Dynamo-tape-as-a-guide method.
This is the 'tinsel' produced after I cleaned up after initial scribing (using the same knife turned sideways & run through the scribed line *gently*):
Then I go through the lines with a cut edge of an emery board lightly to clean up the tiniest fragments...
This is a tedious process, but it ensures a clean panel line with no wonky flares on the edges. And I have to practice because every time I do these, months have passed since my last Viper(s) and I lose my comfort level with the technique.
Next- I scribe the lot of them.