Quick or Fast
I've done it both ways and with no obvious difference but I wouldn't do it minutes before fileding it. Those paints were ment to be fast but you could take your time if you want. Don't pant for the full 24 hrs though it will take a toll on your body. There is one other way for the clearsoft and not for the novice which is to take it appart and paint from the inside. It's the best and you won' suffer scratches but you need to know how to put it all back together.