Enchantment number limit?

Question

I was going through the enchantments that can be used in order to protect/trap one's spellbook and that got me wondering:

Is there any mention/indication regarding whether multiple enchantments can be used on the same spellbook? Can I, for example, have a Blessed Book with the Glamered and Waterproof enchantments as well?

If yes, how do the costs work, assuming you have someone else do the enchantment or buy it in a market.

What about other wondrous items, that do not follow the +X enchantment value philosophy? Would a rope or pair of boots possibly have more than one enchantment on it?

I am of course referring to magic items and enchantments of permanent nature, those made with the Create X line of feats, not things like Magic Weapon spell etc.

EDIT: A friend also mentioned that there may be some non-SRD rules regarding the above in Magic Item Compendium, however I was unable to confirm that. Anyone knows more?

Answer 1

The DMG states on p288 under Adding New Abilities:

A creator can add new magical abilities to a magic item with no restrictions. The cost to do this is the same as if the item was not magical. Thus, a +1 longsword can be made into a +2 vorpal longsword, with the cost to create it being equal to that of a +2 vorpal sword minus the cost of a +1 sword. If the item is one that occupies a specific place on a character’s body (see Magic Items on the Body, page 214), the cost of adding any additional ability to that item increases by 50%. For example, if a character adds the power to confer invisibility to her ring of protection +2, the cost of adding this ability is the same as for creating a ring of invisibility multiplied by 1.5."

So you can enchant your spellbook as you like (unless the spell description specifically restricts it). Other items if they take up a body slot incur the 1.5x extra cost. It goes without saying that the DM has the final say on what can and can't be done in their game world.

Answer 2

In general, wondrous items don't incur increasing costs for increasing numbers of enchantments if they provide a specific effect. Magic items that boost a character's stats are much more restricted, with cost increasing per enchantment and restrictions on body slots. Wondrous items tend to be unwieldy to use in combination, whereas you can benefit from Boots of Striding, +2 Armour, a Cloak of Resistance, and a Vorpal sword all at once.

With regards to your spell-book specifically: go nuts. You can't be too careful when it comes to spell-books!