Scales are used primarily in ceramics to measure ingredients for glazes. The main issue with scales is how accurate they are. When you are making large batches, or when weighing ingredients that are a large percentage of the total glaze, being within a few grams accuracy is fine. But when weight small batches for tests, or ingredients that are a small percentage of the total glaze, accuracy is more important. For example, a colorant like Cobalt is often added as less than 1% of the glaze. So being off by 1 gram can make a big difference to your glaze results.

Therefore, the requirement is to have good accuracy (0.1g) at low weights, and not so much is required at higher weights (1-2g.)

Triple beam scales
have traditionally been used in ceramics because it can measure small weights at high accuracy (.1g) but can also measure higher amounts (up to 2610g with the optional weight set).
Digital (or electronic) scales
are increasing in popularity. With digital scales however, you usually have to get two: one very accurate for measuring small amounts, and one that can measure heavier weights but with less accuracy. (Note: You can get digital scales which can do both but they are extremely expensive.) So a popular combination is one scale that measures 200-300g up to .1g accuracy, and one scale that measures 2000-5000g but to 1 or 2g accuracy. You can probably get away with just the smaller scale if you only mix up glazes in small batches. Or you can probably get away with just the larger scale if you only mix up glazes in large batches. Digital scales require batteries.