Okay, I'm well aware this is a heavily debated topic so wanted to do a poll to find exactly what everyone uses and their thoughts on the subject. I started this hobby in October and have had great success but am working to improve my method. I've heard of the following methods... No plastic lining just paint bottom of tub black - while I've read lining is needed to create a "mini-ecosystem" between tub and lining when the sub shrinks this method blocks the light to stop bottom/side pinning Dark plastic lining - creates the mini-ecosystem and blocks light to stop bottom/side pinning Any color plastic lining - creates the mini-ecosystem but blocking off light isn't needed since its just a signal for mushrooms to fruit much like FAE No lining/no paint - no shrinkage if sub is packed lightly but correctly where light will have little effect on bottom/side pinning