I think I’ve taken Cricut masks beyond the tool’s limit. I can likely use the technique to make the large numbers, but the small (1.5mm/.06″) letters, “CANADA ATLANTIC” on the tank collar are simply too small for the knife-cut masks.
The best I could achieve was with two masks – one for the largely vertical parts, and another for the horizontals. I sprayed the verticals first, and after they dried, applied the second mask and sprayed the horizontals. The two masks enabled the middles of the A’s and D to remain attached, and also assisted with the N’s, which never cut very cleanly in one pass.
I used Tamiya masking tape, which is slightly diaphanous, making the registration of the second mask almost of possible. However, even with see-through tape, it was very difficult to line up the second mask. Despite overlapping the masks by about 0.12mm (.005″), I still have gaps between verticals and horizontals in places.
So, while it may still be the case that Cricut masks are a good way forward for railway insignia, the minimum achievable size is not sufficiently small for my use on #622. Decals or dry transfers, here I come!