On my current project I noted an issue in one step of the painting: I masked off an area, then painted it in several coats.
Because of the intersection of the weather around here and the demands my job puts on my time, those several coats were spaced out over several weeks; during that time the masks shrank, which messed up the quality of the lines.
What factors might be causing this? Is there a technique, or materials, for masking something, then putting two or three light color coats on it over a period of days or weeks that's going to work, or do I have to figure out how to make the whole scheduling thing work out?
Note that I was probably laying the coats on rather thick, and I was using frisket paper of unknown origin that I've had for at least ten years, and maybe 30.