I have used tape, econokote, ultrakote, and occasionally monokote on blue foam. You can use monokote, if the plane is taped beforehand with bidi or strapping tape. Econokote is okay, but it's not very fuel proof. IMHO, Ultrakote is by far the best heatshrink covering for foam, I'm about to try som Black Baron film soon on Ed Kettler's P-70 (A20 night fighter variant)

Cash