It'll have a flat finish when dry enough to paint over, but if I remember right there is a time limit you should not go past before painting. I usually liked it to be dry enough to tack as it leaves a dusty film. Just follow the instructions and you'll be alright. It's been a while, but I don't remember having much trouble with velva seal. I've been a bodyman since 66 and a rebuilder since 78. If you're getting a finish that looks like sticks piled up, it's either old and a little thick or maybe corrupted with something.
Then I lucked out! It looked just as you described. DuPont got back to me on this and said you could topcoat after 4o minutes but no more than 72 hours. After 72 hours you will have to sand it. I let mine dry for an hour. It was dry to touch.