Choosing Paints
New painters visiting large art stores are usually tempted by the large pre-packaged beginner sets, which contain a nicely arranged selection of paints, brushes, and some extras like a pallette or brush cup. My advice is don't go for the sets. They are often very low quality and you will end up replacing them soon anyways. For the same amount of money you can buy a few good-quality colors in single tubes and two or three versatile brushes. These are my recommendations for how to get the most out of your money.
Student Quality vs. Artist's Quality
In the store, you'll see that most brands carry "student quality" and "artist's quality" or "professional quality" paint in the same colors, but the artist's quality paints are far more expensive. Since they come in exactly the same colors and brand, you are probably scratching your head and wondering why you should waste your money on the expensive stuff. As an uneducated artist, I didn't know the difference for years and originally just bought whatever was cheapest. I later learned that the difference between the two grades of paint is that they contain different concentrations of the same base pigment. Professional quality paint is much more concentrated. The student quality paint contains more filler, hence the cheaper price.
My advice is that for your first experience with painting, you should buy small quantities of the student quality paints and experiment with them. If you're still into painting when the tubes run out, buy the professional stuff on your next trip. There is a very big difference in quality, but you won't see a big difference in your results until you have more experience. When you do switch over, you'll notice that the color strength is much stronger in the professional paints, and you won't need to use as much.
Choosing Your First Colors
You'll be dazzled by the number of colors you can buy, but you'll develop more mixing skill (and save money) if you just buy these few basic colors:
1. Ultramarine Blue or Pthalo Blue
2. Cadmium Yellow (or Primary Yellow)
3. Cadmium Red (or Primary Red)
4. Mars Black or Carbon Black
5. Titanium White
You can mix just about any color with these five. These were the only colors I used for my first two years of painting.
If you have money left over, consider:
6. Yellow Ochre (a more natural yellow)
7. Burnt Umber (a rich, all-purpose brown)
8. Alizaron Crimson or Quinacridone Magenta (good for mixing vibrant oranges and purples)
9. Pthalo Green (a bluish, vivid green, with excellent transparency, important if you are going to paint plants)
These four will make your life easier but are not necessary for starting. A good way to practice color mixing is to try mixing colors to match pictures in magazines, things around the house, etc. I used to try to match paint chips. As you develop your style and find the colors you prefer to work in, you'll expand your collection. As a professional artist, I use about 20 different colors of artist's quality paint. You can see the colors I prefer in my color palette.
When I was using student quality acrylic paints, I liked the Liquitex Basics series best, but I didn't really find much difference in quality between the brands. For the professional quality paints I recommend the Golden series. If you're using professional quality paint, I recommend you invest in a Sta-Wet palette and a tube wringer to save paint and save money.
Understanding Paint Transparency
All high-end acrylic paint manufacturers such as Golden, Liquitex and Lascaux hand-paint their tubes to show the exact color of the paint. My preferred brand, Golden, features a series of black crosshatches on a white background underneath where the stroke of paint is painted. You can look at the paint that goes across these crosshatches to check the transparency. In the picture above, you'll notice that the Quinacridone Burnt Orange, in the middle, is much more transparent than the Raw Sienna beside it, since you can see that the black crosshatches show up well through the paint. The Raw Sienna paint looks chalkier and more opaque by comparison. The other colors have a moderate transparency. If you were to paint over a dark surface with these two colors, the Raw Sienna would lighten it a little bit, while the Quinacridone Burnt Orange would only tint the color. I used to think that any color could be made transparent if thinned down enough, but this is not exactly true. The opaque colors, such as Raw Sienna and Titanium White will have a chalky texture if thinned out, but transparent colors will thin out to a smooth inky consistency. Even the transparent colors can appear opaque of applied thickly enough, but when you thin them out, you can see the difference.
The outside of the tube tells you a lot about the paint. Some paints are mixtures of other pigments, like the one above. Below the name (in this case, Light Violet) you can see the pigment mixture (Dioxazine Purple and Titanium White). In general, it's better to buy the straight colors and mix them yourself, especially if you are starting out on a limited budget. When buying paints, I usually check to see if they are mixes, and if I already have the colors that they are mixed from, I don't buy them. Two exceptions in my collection are Payne's Grey (a mixture of Carbon Black and Ultramarine Blue) and Green Gold (Pthalo Green, Nickel Azo Yellow and Hansa Yellow Light) because I use both colors frequently and the mixes are convenient for getting consistent results. This is my color palette.
Below the pigment name is the universal pigment number, which is handy if you're buying paint in a different brand that you're not used to. The lightfastness is found below that, and is a measure of how well the pigment will stand up over time. Most acrylic paints are very lightfast, but some colors are better than others. This color is rated II (Very Good) but most of Golden's paints are rated as I (Excellent).
If you're ordering your paints online you'll notice that it's difficult to see the transparency when you don't have the tube in front of you, and the web colors usually don't accurately replicate the paint color. I recommend asking the paint company for a hand-painted color chart, which has little swatches of each paint, along with the properties. If you ask nicely you can get one included with your order so you have a reference for next time.
Paint Pigment Series
If you've been shopping for paint, you'll notice that intermediate and professional quality paints are priced by series. Student quality paint contains less pigment and is usually priced uniformly for all colors. The series number is based on the cost of the actual pigment that the paint is made from, with paints in Series 1 or 2 costing a fraction of those in Series 8 or 9.
Acrylic, watercolor and oil paints are made out of the same basic pigments, suspended in different binding media. It surprised me to learn that many paint colors are still made with natural, earth derived pigments. Depending on where the pigments come from and how they are processed, some are more costly than others to produce. There are a few synthetic versions of expensive colors, often called "hues," that are much cheaper but perform differently.
Usually the motivation for switching to a synthetic pigment is cost. My favorite paint color, Ultramarine Blue was historically produced from the semiprecious stone lapis lazuli and was very expensive. In the 15th century, it was so expensive that an artist would charge extra on a commission if their client wanted blue in the painting, just to cover the extra material cost. Now that a chemically identical synthetic pigment is available, Ultramarine Blue can be produced cheaply, and is usually Series 2 when you buy it in the store. Other synthetic pigments, such as the Quinacridones, are more expensive to produce, and therefore more expensive to purchase in the store. Another one of my favorite synthetic colors, Quinacridone Magenta is Series 7, and was developed as a lightfast alternative to the older Alizaron Crimson.
Sometimes, synthetic alternatives are made to replace paints that are hazardous or derived from animals. The beautiful Vermillion Red is very toxic, and has been replaced by synthetics in recent years. Vermillion is still available in artist's paint, but very few artists use it. I always avoid any colors that are toxic.
Paints with a higher series number are not necessarily better or more lightfast than their Series 1 counterparts. I've noticed that the higher series tend to be more transparent, which gives you more options for glazing, but this is not always true.