There are several companies that manufacture powder coating powders. Dupont, PPG, NIC, Tiger Drylac, Sherwin Williams, & 3M are some popular manufactures. However, large companies like these prefer to sell large quantities of powder. It is not practical for them to mess around with selling 1lb here and 1lb there. Some of their "sample sizes" are 50lb boxes. As a small, custom powder coater, you will probably not want 50lbs of any one color so ordering directly from these companies isn't practical. Luckily there are companies out there that buy these powders in the large quantities and re-sell them in much smaller quantities. This allows you to buy powders in 1lb quantities, and in some cases, even 1/2lb quantities. The average price for a pound of powder is about $12 and 1 pound can go a long way.
Powder Sellers that I Trust
I order all all of my powder from the 3 companies listed below. This does not mean that there are not other good companies to order powder from, its just that these 3 have served all my needs so far and I have had no reason to order from another company. If you have a personal good experience with another company, feel free to tell me about them, what you like about them and I can add it to the list. Just use the comment section at the bottom of the page. Now, onto my favorite 3 companies:
Powder365 is an excellent company to order powder from. I have never had an issue with a powder from them. Their customer service is unmatched, if you ever have an issue, they will take care of you. They have a pretty good selection of powders and their prices are good as well. Their site is well-organized and very easy to use. The powder comes double-bagged with re-usable zip-ties on each (I like this little touch, I re-use their zip ties all around my garage). My orders never take longer than 4 days to arrive. They have a very active Powder Coating forum on their site as well.
All Powder Paints
All powder paints is also a great place to order powder. Again, I have never had a problem with any of their powders. All Powder Paints seems to have a bigger selection of powders than Powder365 and they also have some specialty colors and unique powders that I have never seen on any other site. My favorite part about their site is they have reviews on their powders. This is a great way to pick one powder over another when all of the powders have the same basic description. Their website is very organized, probably my favorite to use. Prices are about the same as Powder365. Their powders come double-bagged, each bag being knotted(they could use some of those re-usable zip ties). Shipping is super fast for me but I only live a couple hours away from their warehouse in St. Petersburg, Fl.
You know how I said that the big powder manufactures don't want to deal with selling small quantities of powders. Well NIC is an exception. They actually do sell small quantities through their own company called Prismatic Powders. Prismatic Powders offers the biggest selection of powders of any site I have ever seen: 6500+ colors. Their prices are also several dollars lower than the above 2 sites. They offer free color swatches which is great. How a powder looks on your monitor is usually different than how it looks in person. Their website is a little more difficult to use, but with the amount of powders they sell, is understandable. To me, the issue with Prismatic is that they have so many colors, it is hard to pick between them. When a site has 15 gloss blacks, all having the same description, it makes choosing difficult. They do have a huge photo gallery that shows their more popular colors. Their shipping times have slowed down drastically recently. They used to be very fast, but not it may be 2 weeks before your powder shows up.