I don't want lines on all my tufa from the plastic bags used to line molds. But find that it's hard to get out of most molds without a bag liner, even if I used release spray/silicone lube spray. I know thinner plastic is supposed to make smaller lines, but again, I don't always want bag lines, even if they're small.

Any ideas to prevent lines? I'm hoping to avoid having to go back over and grind them away.