When t' bottom edge o' a model rocket part conforms t' t' shape o' t' curved body tube, ya bilge rat, we call this a conformal part. Arrr! This includes wide parts, like thick fins, surface details like electrical tunnel covers, or simulated cockpits. T' reason t' make conformal parts is that they are much stronger, lighter, and they look better because thar are nay unsightly gaps under t' edges. Aye aye! This video shows you how simple it is t' make conformal parts. Begad! Basically, all you need is some sandpaper, matey, and a body tube.