5A – Great top hard to fault acoustically or aesthetically
4A – Supurb top allowing slight off-quarter at outer edges & other slight anomalies
AAA – Excellent top allowing some noticable imperfections or character
AA – Fine top allowing minor runout, quarter drift, grain to 8 rings/inch, some color
A – Good top allowing normal range of Red Spruce character including more flex & hard late grain
B – Servicable production grade top where budget is primary consideration
Sizes
Full – 8″ x 22″ or larger for Dreadnought or Jumbo
Mid – 7.5″ x 20″ or larger for OM, Classic
Small – 6.5″ x 19″ or larger for O, etc.
Parlor – 6.2″ x 18.5″ or similar for Parlor, etc
Arch Mandola .8-.3 x 6.2 x 16″ wedges
Arch Mandolin – 7/8 – 3/8 x 5.5 x 15″ wedges