In the 3.5 Dungeons Masters Guide there is this section that is very important for this discussion:
DMG3.5 wrote:Weight: The notational entry for many wondrous items ends with a value for the item’s weight. When a weight figure is not given, the item has no weight worth noting (for purposes of determining how much of a load a character can carry).
Online source:
D20srd: Magic Item Basics
This means that a scroll's weight is negligible and the reason to use a scroll case is mainly to protect the scrolls, a scroll case's weight is 0.5lbs. A weight of 0.1lbs isn't negligible.
A scroll has AC 9, 1 hit point, hardness 0, and a break DC of 8, so there is a very good reason to use a scroll case as a scroll breaks easily without.
A scroll case is usually made of ivory, jade, leather, metal, or wood, and most scroll cases are inscribed with magic. As such a scroll case's AC, HP, Hardness and break DC would be different depending on the material its made of and any protection magic placed on it.
So to give you an idea I've listed some materials with some important stats, though AC would be around the same, no point in listing that, as for weight and break DC they vary and depend on various factors, so those cannot be accurately listed below.
[th=3]Table: Substance Hardness and Hit Points[/th]
[tr][th]Substance[/th]
[th]Hardness[/th]
[th]Hit Points[/th][/tr]
[tr][td]Paper or cloth[/td]
[td]0[/td]
[td]2/inch of thickness[/td][/tr]
[tr][td]Rope[/td]
[td]0[/td]
[td]2/inch of thickness[/td][/tr]
[tr][td]Glass[/td]
[td]1[/td]
[td]1/inch of thickness[/td][/tr]
[tr][td]Ice[/td]
[td]0[/td]
[td]3/inch of thickness[/td][/tr]
[tr][td]Leather or hide[/td]
[td]2[/td]
[td]5/inch of thickness[/td][/tr]
[tr][td]Wood[/td]
[td]5[/td]
[td]10/inch of thickness[/td][/tr]
[tr][td]Stone[/td]
[td]8[/td]
[td]15/inch of thickness[/td][/tr]
[tr][td]Iron or steel[/td]
[td]10[/td]
[td]30/inch of thickness[/td][/tr]
[tr][td]Mithral[/td]
[td]15[/td]
[td]30/inch of thickness[/td][/tr]
[tr][td]Adamantine[/td]
[td]20[/td]
[td]40/inch of thickness[/td][/tr]
Online Source:
D20srd: Exploration