Ames, Typographical antiquities, 1749 (4I4v)

This blank verso unsurprisingly shows bleed-through from the recto's errata list and binder instructions. But it also shows off-set ink from the index: notice the columns of text and the heading. If you look closely above the bleed-through of "Directions" you can see a series of numbers starting "263, 300, 304"; next to the bleed-through you can see a series of "S"s lined up vertically, suggesting that this is part of the "S" entries. If you turn to sig. 4I1r, you'll see an entry for John Skelton that matches these characteristics. In a quarto, pages 1r and 4v are both on the outer forme, and so when those sheets were hung to dry, the ink from one page could easily transfer to another, as we see here.

Cato, Moral distichs, 1735 (A1v-A2r)

On the blank page shown here, you can see the raised letters from the impression of the type used for the title page.

Donne, Juvenilia, 1633 (F1v, raking light)

Imaged under a raking light, this blank page reveals a great deal more texture than images usually do, including wrinkled (or cockled) paper, vertical wire lines, the bite of type as it pushes out the paper from the other side, and the bite into the paper from some uninked (or blind) type in the middle of the page ("These eleven Paradoxes"). Some copies of this edition have this imprimatur inked and legible; others, like this one, seem not to have included it, although the type was clearly left in the forme even if it didn't print. (Compare this image to the one under usual flat lighting to see how different lighting shapes what we see.)

Donne, Juvenilia, 1633 (F1v)

This blank page is surprisingly busy. There's ink bleeding through from the other side (you can see the running title "PARADOXES" at the top and the signature mark "F" at the bottom of the page) but there's also offset from the facing page ("PROBLEMS", the title of the next section). It can sometimes be hard to tell the difference between bleed-through and offset in digital images if you can't also see the facing page, but one clue is to look for different colored ink. But if you look at this page under raking light, you'll see there's even more going on than is apparent in this image.

Gianicolo, Type specimen, 1529 (verso)

There is very little bleed-through apparent on this blank verso, although it's hard to tell if it is due to how this broadsheet was printed or how it was photographed.

Indulgence, Augsburg, 1481 (verso)

On the back side of this indulgence, you can see the creases where it was folded up for safekeeping and the later repair work done to stabilize it.

Keimer, Elegy, 1723 (1v)

The back of this broadsheet shows the ink bleeding through from the front, as well as the small patches that have been made to repair the damage from being folded.

Nostradamus, An almanach, 1562 (fol. 1v)

Although this almanac is for the year 1562, a user has added notes for a number of later years, including 1581 and 1589, as see here on the blank verso of the title page.

Ogilby, Aesop, 1668 (pg. 48)

The blank space on this page decisively separates the fable and its moral.

Ogilby, Aesop, 1668 (plate 18 verso)

The blank verso of the leaf of a hand-colored intaglio print shows where some of the inks have bleed through.