Problems
Ribbon does not form
Crooked ribbons
Sections are irregular, skipped, thick or thin
Sections are compressed, wrinkled or jammed together
Sections crumble, specimen may tear out
Split ribbon or lengthwise scratches in ribbon
Knife rings on upstroke and sections are scratched
Sections lifted from knife on upstroke
Sections stick to knife & Sections fall out of matrix or show compression different from embedding medium frame
Other
Undulations in the surface of the section
Sections fly and stick to parts of microtome or other nearby objects
Knife does not hold its edge