Also know that while the HOK primers are killer. It CAN NOT be painted directly over you need to spray a KO-Seal over it. House of Kolor has no solutions that allow you to paint directly over their primers. None, nada, zip.
Ko-Seal is a great base and you can tint the metallic or white to be your first layer for artwork and such. Ko seal would be a great bass for a swirl I believe though especially their metallic, you can even tint it.
And if your going to do it use all HOK products, color, clear and primer/sealer.
People will tell you to mix brands but its just not a good idea, brands mix different solvents and levels, so while it may be okay you don't know what it will do in the long run. Spraying on a piece of scrap or test panel just tells you its not a bad idea for a day or so, you don't know what will happen in 5 years.
Before you commit to HOK, read the tech manual its on their site.
I would buy my HOK from Coast Airbrush(coastairbrush.com). They will match anyone's price and provide superior support and service.
The other advantage of Coast is they don't premix thier HOK small quantities. What's the big deal:
1. Control, you don't know TCP Globals reduction rate. You want to control this, or at least know what it is. For a swirl I would way over reduce to get more time and a thinner film.
2. Price, reducer is way cheaper than paint or kandies. So while TCP seems competitive they are really pulling the wool over your eyes.
3. Shelf life. Reduced paints and especially the kandies have about a week of shelf life before they start to get grainy and funky when you spray. Subtract shipping time from this.
As always your mileage may vary.