Not sure I'm clear on the question.........are you talking individually wrapped 1" or 2" going into a bigger block with cutout hole??? or say a 4" cube going onto a slab? Wherever the rockwool pieces touch, there shouldn't be packaging between.........but you can leave the plastic sleeve on the slab. I use 1" cubes for rooting clones...then put them into a 4" cube........My 1" cubes come unwrapped as a flat of 98...... For the 4" cubes, I sometimes leave the sleeve on and sometimes take it off...........I put the 4" cubes in 6" pots just for spacing and to keep them from sending roots into the next cube over
