So I have been working on an order of backpacks that have a plastic type backing on the canvas. Seems to make a mess of the needles. Is there a trick of the trade for dealing with this? The job is turning out fine, I've switched needles once just because the plastic stuff is sticking to them. I'll definitely toss the ones I'm currently using too at the end. I didn't know if this would be an application for those ceramic needles or something like that. I am assuming it is the heat and friction melting the plastic. I am currently running about 700 STM. It about a 3K stitch logo with three color changes (within two colors). I have been using a tear away backing and it's all sewing out fine just messy with little trills of the weird plastic liner building up on the needles. I would be really freaked out but the bags have a design from the manufacturer a little lower than ours and I see bits of the same stuff stuck in their thread too so I think they had the same thing going on. We started cleaning any loose stuff off between each bag to avoid having it down getting caught in the stitching.