I am using resin. It's around 4 oz without weight. The bottom half of the bait is pure resin and the top part is resin and microballoons so it would be more stable. It is already a slow sink without any weights, but I'm adding te weight to keep it from rolling. I have slimmed down the head quite a bit and I might need to fill the gill slits in. Im thinking that has a lot to do with it. I'll swim test soon to see if that helps. thanks all