See-through parchment: a leaf and its back

The parchment is thin, and on many scans the paint and ink of the back show through the leaf. Here the mirrored back of the same leaf is placed under the front and aligned to the edges of the parchment. The slider makes the top layer transparent, so you can see what bleeds through and what belongs to the leaf itself. The back can be moved by hand: with the sliders, by dragging with the mouse or a finger, or with the arrow keys.

How to read it

The alignment is automatic - by the top, bottom and outer edge of the leaf against the black background of the Yale scans; the gutter is not used, since the stack of neighbouring leaves is visible there. Accuracy is a few dozen pixels on a scan 3200 pixels high: enough to tell which stain comes from where, not enough for measurements. Fold-out leaves (f67-f72, f85-f90, f94-f95, f100-f102) are not included yet: one scan holds several panels.

What it gives: the green and brown shadows in the margins of a front side usually turn out to be leaves and roots of the back; what matches the back in no position is a trace of the leaf itself (washed paint, a stain, a correction). It gives no reading of the text and implies none.