and more molds with wire keepers
I have the collarless pro series molds in all sizes from 1/32 to 1/2 and can slip a piece of fine stainless wire along side the hook's shank with the mold closed in every one of them. I cast the jig with the wire straight and then bend and trim when you are ready to paint.
Barlows tackle's 2013 catalog has the wire I use on page 30 in the lower left corner. I use the .013" wire and the 30 foot coil will make a bazillion plastic keepers. I cut my wires initially at about two inches and use a fine point needle nose to put a slight interference bend in the "very end" that gets cast in the head....you don't need much. When I trim the wire off after casting, the trim end gets used for the next round. You can also simply trim the wire to the length you want after casting and just lift it up off the hook's shank slightly and leave it straight.
On crappie sized heads you do not need a super heavy wire at all and even thin wire is a pain on the tiny heads so I also use a lot of super glue on those collarless heads. If I put just a rub of glue on the hook shank with a new plastic and they'll stay put for a long time. For the most part I tend to limit wire use to heads of 1/8 or more where walleyes and other toothie denizens tend to tear at the plastic more.