The difference between a spaghetti top and a slip top is not in the straps, but in the material of the top. A spaghetti top is any top with thin straps. A spaghetti top can be made of any material, including wool and leather. In contrast, a slip top is made of satin (of silk or a plastic blend that looks like silk from a far distance). To conclude, a slip top is a spaghetti top made of satin, a satin top with thin straps. A spaghetti top is any top (satin, cotton, linen, wool) with thin straps.