Fix

src/art/artJS.tw

@@ -1842,7 +1842,7 @@ window.VectorArt = (function (artSlave) {
 
 	function setButtSize() {
 		/* Size calculations - needs to be done even for amputees */
-		buttSize = Math.clamp(slave.butt, 1, 7) - 1;
+		buttSize = Math.clamp(Math.trunc(slave.butt), 1, 7) - 1;
 	}
 
 	function setHairLength() {