I'm with AliKat. I wouldn't use anything that's breakable or can break a needle without it being made especially for the longarm. Remember the longarm's hopping foot goes a million miles a minute and can cause numerous problems....and unless the item is at least 1/4" thick and doesn't block your view or ability to go around it, then it's useless. For doing curves a good source of 1 set of rulers for any size curve is
www.handiquilter.com.