For speed bag work, use lighter, non-padded gloves in either vinyl or leather to protect yourself from scrapes and skin damage. If you're going to be working on a punching bag, get bag gloves with cushioning to absorb some of the impact. When working on a punching bag, use your bag gloves, not boxing gloves. Sparring gloves are great for protecting you and your opponent. They aren't great for your form when practicing.

There's been a trend towards MMA style open finger gloves for heavy bag work. The open finger gloves are a good choice, particularly gloves that have a palm bar. They often can provide a better fit, whether your fingers are short or long, and the palm bar allows you to make a better fist.