just wondered if there is a source .... I make slot or trough calls and they are killers with ceramic... i get tired of cutting up the rounds that are available and having a lot of waste when I'm done .... i've thought about making a half and half call out of the scraps 1/2 ceramic 1/2 aluminum or slate....
by the way my favorite is a small walnut call with a piece of broken KH Old Yellar in it