When you're shopping for paintballs you should consider the level of play and performance you want and expect. Paintballs are made in different grades according to their use and price point.
White Box/ Seconds Paintballs - These are the cheapest paintballs you can buy. There are various reasons why paint ends up being sold as White Box Paintballs or Factory Seconds Paintballs. Sometimes the paintballs are old, or a batch were odd-sized, oval shaped or heavily dimpled. Since they do not meet a brand's typical quality control standards then they get repackaged and sold at a reduced cost. While a great price you can expect less accuracy, more bounces or more broken paint with seconds.
Recreational/ Field Grade Paintballs - This grade of paintballs are the next step in paintball quality and performance. Recreational Grade and Field Grade Paintballs typically are made with a slightly thicker, more resilient shell or shell material that is recycled excess from other manufacturing batches. This keeps the cost lower and prevents the paintballs from breaking in field rental markers. The paint fill is usually thinner for leaving bigger splats and easier clean up. Recreational grade paintballs perform a bit better in cold weather conditions than others. These are the most commonly purchased paintballs.
Premium Grade Paintballs - These paintballs are an upgrade in accuracy and marking ability. Premium grade paintballs are always first run shell material made under tighter quality control for more roundness and better seam. The shell is a bit more fragile to break on target easier, and the fill is thicker for improved accuracy. You can expect much higher performance with premium grade paintball than field grade.
Tournament Grade Paintballs - These are what the professionals shoot for the utmost in performance. Tournament grade paintballs have a thinner shell made under more controlled and labor intensive manufacturing processes. They are made to be as perfectly round as possible, and just durable enough to be fired reliably while easily breaking on target. The paint fill is thick, often like paste so that cheaters cannot easily wipe off a hit. Tournament quality paintballs are best used with high end, low pressure operation paintball marker because they are often too fragile to use in low end markers that are harder on a paintball when fired.
Paint Grenades - Sometimes you need a little extra to take out that strategic bunker. For those times you need a Paint Grenade to clear out multiple opponents. Paintball Grenades are pressurized tubing that bounce and squirt paint everywhere on impact. They are especially useful in scenario games, where sometimes an objective can only be neutralized with a grenade.
Re-Usable Paintballs - There are several brands of re-usable paintballs on the market. These are typically made of rubber or similar material so they can be shot, picked up, and shot again. These are perfect for target practice, working on your snap shot, and tuning your marker without wasting expensive paintballs or making a mess. Some re-usable balls can be used in games against others while some are for target practice only, so be sure to read what grade your reusables are meant for.