Silken tofu?

[Atlas]

There are several brands of silken tofu, the most common is Mori-nu and it's shelf stable so sometimes you'll find it on a shelf and sometimes in the cooler. Silken tofu itself comes in several levels of firmness as someone else pointed out and firm or extra firm is usually the one used. The different coagulants are what give tofu it's various textures. Non silken tofu (Chinese style/regular tofu) isn't quite as smooth as silken, especially when blending. It'd be a decent substitute if it only called for a small amount, but for something like tofu chocolate mousse or a tofu peanut butter pie it'd be worth it to track down the silken tofu. I think it's the easiest to find at regular grocery stores because it's shelf stable.