The gross size sections (gross section object) are included in the paraffin using special mold (Leukhart bars). The black coloration is due to Indian ink left on the surface of the tumour.
Beginning of the 5 microns-thick ribbon cut. The ribbon is tick up delicated with a tweezers. This gesture is accompanied by a gentle blow in direction of the block while turning the handle in a regular movement. Avoid fans and draughts.