BOOKSHELF

A bookshelf is planks wrapped around books, and the planks were never the problem. Each of the 3 books inside takes paper and leather to make, and leather means a cow farm or a hunt, a slower chore than the 6 planks around the outside. Buying the finished shelf skips that chore entirely.

15 of them ring an enchanting table, which is the reason most people ever need more than a handful, and building that ring from scratch means farming enough cows for every book in every shelf. A Librarian selling the finished product turns that whole supply chain into a straight emerald cost instead.

It is also a trade you meet early. He carries it from novice, the tier every librarian starts at the moment he claims a lectern, so there is no climbing to do before the offer is on his shelf.

One job, one price. The Librarian asks 9 emeralds for a bookshelf the moment he reaches novice, and the number does not move between one librarian and the next: it is written into the trade file rather than rolled inside a range.

No villager buys a bookshelf back off you. The only place it changes hands is here, and the only direction it travels is out of the librarian's shelf and into yours.

Bookshelf sells for as little as 9 emeralds, from the Librarian at the Novice tier, and nothing else on that list costs more. The price is fixed rather than rolled, so a second Librarian will quote you exactly the same.

The Librarian at its novice tier asks 9 emeralds for a bookshelf. 8 of the 72 villagers that pay emeralds, emptied out:

9 diamonds against 288 rotten flesh for the same 9 emeralds, 32 times the carrying, and the shortest wait is the Fletcher at 5.6 real minutes of shelf, gathering not counted.

Any unemployed villager next to a lectern becomes a librarian, and this row is on his shelf from the moment he takes the job, no levelling required first. Breaking the lectern before he settles loses the profession along with every trade on it.

Once open, the slot sells 12 bookshelves before it locks, and a restock refills the same offer at the same price rather than handing him something new to choose from.

Curing a zombie librarian caught early is worth doing before a big buy. The discount applies to every trade he carries at once, bookshelf included, and it never expires once it lands.

12 bookshelves empty one slot, and the librarian needs 2 real minutes at his lectern before it fills again. A Minecraft day runs 20 real minutes, enough time for two of those refills to land.

Stand there for a full day and one librarian will sell 24 bookshelves, more than enough to cover the 15 that ring an enchanting table with a run of them left over for a second library.

Cure before the big buy. A full ring of shelves at a discounted rate is real emeralds saved, and curing costs nothing beyond a golden apple and a splash of weakness once you have a zombie villager cornered.

The same Cartographer buys paper at 24 an emerald, so a sugar cane farm is a way to fund the shelves you are buying, not just a separate errand.

Also on the Librarian's list: enchanted book, book, lantern, ink sac, glass, and book and quill, the rest of what one lectern can put on offer.

The discount is worth reading up on before you commit to a full slot, because it applies to every price that librarian quotes afterwards, not just the shelves. How curing works.

A bookshelf is six planks around three books, and breaking one without Silk Touch gives the three books straight back and no shelf. That is unusually forgiving: the expensive half of the recipe survives, so a wall of shelves is a store of books rather than a sunk cost.

The reason to have any is enchanting. Shelves placed around a table, one block of air between them and the table, raise the levels it will offer, and a full ring is what gets you the top tier. Anything blocking the gap, including a torch, switches that shelf off.

Buying them ready-made saves the paper more than the wood. Three books is nine paper and three leather, and leather is the part that takes a farm.