Flocked vinyl heat transfers work in the same way as other HTVs. You print your design and use heat to stick them to your garment.
The difference is in the texture of the surface. Where most HTVs have a smooth surface, a flocked vinyl one has an almost furry look and feels a little like soft suede. It is thicker than other vinyls and it will stand out when pressed on. This will give any project a 3D effect.
Kids will love this vinyl because it's so soft to touch and using it on children's clothes can be great fun.
You can use this type of heat transfer vinyl anywhere where you can use other vinyls, but be careful if using it on items which may be prone to the weather.
If you really want to add an extra dimension or create something unusual, you can use a flocked vinyl instead. They are available in a wide assortment of colours, just like other HTVs.