It’s easy to mask off a cylinder, whether the dividing line goes around or lengthwise or even diagonally along the cylinder (assuming it’s a straight line to be masked). Masking a conical transition, though, is a different story: though the line around might look straight and parallel to the ends, it’s not: it’s really curved, if you flatten it out. How, then, to mask it using straight-edged masking tape?

Answer: use masking tape with a curved edge! I have the transition painting template, and this is shaped to follow the conical transition so you can draw a nice dividing line. It was simple to cut the masking tape using the template as a guide, then mask using the cut, curved edge of the tape along the dividing line.

Voilà! A nice, sharp masked dividing line between the segments of the roll pattern.

The Interstage/S-IVB is now masked, except for one more coat of paint-on mask over the retro-rockets on the Interstage, and then removing the masking tape used to edge the paint-on mask. With any luck, we’ll paint the black on Wednesday!