Paper: Print on high-quality 110lb cardstock (US Letter size) to give the final label a heavy, premium rigidity.
Scale: When your print dialog opens, set the scale to "Actual Size" or "100%". Do not use "Fit to Page", or the dimensions will not fit your slabs.
Cutting & Scoring: Cut out the entire double-tall rectangle block. Then, use a bone folder or a butter knife to gently score the faint gray dashed line in the center.
Folding: Fold the label in half along the scored line. You now have a perfectly aligned, double-thick front and back label ready to insert into your slab!