Wire-O books from Wikipedia

Generically called double-wire binding, because two metal wires go through each of the holes drilled through the book block, Wire-O sounds like a trade name, though I can’t find that it was.

Depending on thickness of book there are two “pitches” of Wire-O, meaning two different numbers of holes per inch. For smaller books 2 holes per inch, and for larger ones 3. Two-pitch wires will be used up to 9/16″ bulk, while 3-pitch can go up to 1¼”. As with all other mechanical binding techniques the folds down the spine will be chopped off and holes drilled through the book block.

Normally the cover is treated in the same way as the other pages: i.e. any cover spine is chopped off. But one of the neat features of Wire-O is that you can, by dint of cunning folding, do a book with a spine left in situ, so that when the book is on the shelf you can identify it, not just see an array of wires. This picture, from Print Finishing Specialities, shows the idea clearly.

 

 

 

 

 

 

 

 

For other styles of binding search “binding styles”.