Makeup brushes come in endless shapes and sizes. The major difference with brushes for cosmetics is the bristles, the part of the brush that transfers the makeup from the palette and applies it to your face. Choosing which kind of brush is right for your skin is often a matter of trial and error. Some brushes may be too rough when applying makeup, and some may not stand up well to frequent use. If you're an animal lover, you should also pay close attention to what materials the bristles are made from.
Natural brushes, whose bristles are made with various hairs from animals, are more expensive than synthetic brushes. Natural bristles tend to hold color pigments better than synthetic offerings and create a softer, more natural look on your skin. If you're an adamant animal rights supporter, however, you'll want to find out if the brushes were made humanely before buying. Natural makeup brushes include bristles made from the fur of various animals, including squirrels, goats, badgers, horses, minks or sable, and the condition the animals are kept in is often less than ideal.
Synthetic bristles are man-made and are usually either nylon or polyester filaments. They can be created to increase their color-carrying ability by blending fibers. Often, synthetic filaments are dyed and baked to make them softer and more absorbent and are less prone to damage from makeup and solvents. They're easier to keep clean than natural hair brushes because the filaments don't trap or absorb pigments, and they're better suited for layering powders or concealers since they hold up more solidly to makeup. Also, synthetic-fiber brushes are a great fit for people with allergies to animal fur.
Just remember that regardless of your budget or the kind of makeup you use regularly, finding the perfect brush is a matter of personal preference. Yes, chances are that a brush that costs $50 will work much better than a cheap, bargain-bin buy, but, like makeup itself, what works for you is all a matter of personal preference. If you find a quality brush that makes you look your best, buy it and don't look back, and as long as you take care of it, it should serve you for years to come.