There are many different types of prepared catfish baits for catching channel and blue catfish. These baits are often referred to as "stink baits", but while they might smell quite foul to some anglers, the smell really attracts catfish.
Stink bait is a very broad term and there are several different types of these prepared baits with the most popular forms being dip baits, punch baits and sponge baits. The names of these baits has much to do with the texture and consistency of them, how the hook is baited, and the type of hook or "lure" that you use for fishing with them.
Punch baits are the thickest of these three different types of baits and have gained a huge following over the past ten years. Punch baits are very thick and packed with fibrous material, which makes them much easier to bait a hook with and keep them on the hook.
Unlike dip baits, which require the use of a dip tube, or worm or sponge baits that require the use of a sponge hooks, punch baits are fished with a plain treble hook and don't require the addition of any springs, sponges or other implements to hold them on the hook when catfishing.