Comics are graded more finely than most paper collectibles, and the vocabulary rewards precision.
The scale
The standard runs 0.5 to 10, with descriptive names attached to the bands — poor, fair, good, very good, fine, very fine, near mint, mint.
As with coins, "good" is low. It means heavily read.
What the grade is made of
Spine — ticks, stress lines, rolling, splits.
Corners and edges — blunting, chipping.
Cover gloss — present or worn away.
Staples — rust, tears at the staple, migration.
Page quality — white, off-white, cream, tan, brittle. Graded alongside and stated separately.
Flatness — any curl or bend.
Restoration
Any work done to improve it: colour touch, tear seals, cleaning, pressing, trimming.
It must always be declared. Undeclared restoration is the commonest serious dispute in this category, and it is detectable — so concealing it does not work. A restored book honestly described has a market; a restored book sold as unrestored has a refund.
Pressing
Worth naming separately because opinion is divided. Many consider pressing acceptable and non-destructive; others want to know. Say if it has been pressed.
If you are not a grader
Say so, and give a band rather than a number. "I would call this very fine, but I do not grade" is honest and protects you.
Questions people ask
Does page colour affect the grade?
It is stated alongside it and it affects price.
Is a pressed comic restored?
Usually treated as distinct, but declare it either way.
What is a reading copy?
Low grade, bought to read. An honest and useful category.