When I first started making soap, I lined my wooden molds with meat wrapping paper. It was a miserable job, getting all of the measurements exact as well as very expensive. I came by another technique quite by accident and would like to share it with you. I changed over to lining my molds with new black garbage bags which I cut into sections to fit my wooden molds. I found that I could get a nice square loaf if prior to placing the black plastic I poured a cup of warm water into the mold, rolled it around so that the bottom of the mold and sides were wet, and then poured out the excess water. The plastic now sticks to the sides and bottom of the wooden mold. You can push out any air bubbles as well as pushing the corners right into place. You can reuse the plastic several times, cutting costs. Cheers! Cody Wellard