Enc: [protectionscrollencumbrance]	IS: [protectionscrollsave]	Aura:	XP: 2500	GP: 12,500
Scrolls	-	time: 5s	-	DMG

The reader of the
scroll is protected from all forms of acid, up to a damage limit of 20 HD or a time limit of 9-1 2 turns (d4 + 8), whichever comes first.

Thus,
the scroll would provide safety from three separate breath-weapon attacks
by a black dragon of smallest size (normally 6 HD of damage
per attack), with a small amount of protection yet unused - assuming
that the attacks all take place before the time limit expires.