A good example might be this, A guy wants to build a 70" bow from a 3/4" thick board. 3/4" will have considerable flex here so will need a longer gradual fade to keep the handle from popping off. In a case like this the lam would actually be bending in the fades so it would be stretching the intention of self bow a bit but at the same time this is done routinely with board bows. I have always felt primitive should be dropped and just switched to wood bows.