Glossary

Jacket
The paper cover sometimes called the "dust cover" of a hardbound book.
Jaggies
Jagged edges or lines; unsmooth caused by the limitation of pixel size in digital printing.
JPEG
Joint Photographic Experts Group. A "lossy" compression file format. Data is lost permanently when reducing an image for transfer.
Jumping
The loss of colour to colour relationship in the printed image due to inaccurate printing in one or more colours. (poor registration).