Some Mfg's even say 400 degrees for 20 min to get the best out of a Chrome Powder paint. I use between 390 and 400 degrees for 17 minuted and I give it the last 2 minutes to reach temp in my little toaster oven and if it was preheated then it would be 15 Min.
Oh one group that has a special undercoat of Chrome and Black and then a candy color over. They insist on 20 minutes at 400 degrees and they said the base needs that cured at 400 before the candy coat is put on. So you end you curing that kind two time, lol!
The CSI temps they have given out for many years now, most say 392 for 15 minutes and that is lead surface temps. The give other options like a lower temp for more minutes, but they also tell you extended time will make the color darker! Is why I use the 15 minute plan on every color except Pearl White and that is a special case and gets 325 for 20 minutes. I have got their list from them several time over the last 12 years or so and have spoke to them on the phone many time about all this.
Okay edit time to add in a picture of the Illusion painting I have done. This is the kind you have to cure the base coat and then Candy coat and cure again!