Height and Width
If the frame is to be hung portrait (more tall than wide) then the height is the longest length. If the frame is to be hung landscape (more wide than tall), then the height is the shortest length
Image Size
The measurements of artwork that are to be visible within the frame and mount, including borders, if these are to show. Image size is not always obvious and can be a matter of taste, eg a customer may want a tiny image framed surrounded by a large expanse of paper. Sometimes referred to as window size, since it is the size to which the window aperture is to be cut.
Rebate Width
This is the space at the back of the frame into which the glass, back and/or mount fits. Frames are made so that the rebate size is a few mm larger than the size specified when ordering. If we didn't do this then the glass, back, mount or, indeed, artwork wouldn't fit comfortably.
Rebate Depth
The inside distance between the back of the frame and the lip onto which the glazing sits.
Acid
Acid attacks cellulose fibres by shortening them, causing paper to discolour, become brittle and eventually turn to dust. Exposure to light and damp accelerate this process. Acid is generated by the lignin (tree sap) in paper. It can also be introduced by chemicals used in paper manufacture, framing materials and atmospheric pollution. All
picture and photo mount card
sold by eframe is acid-free.
Mat, Matting, Mattboard
The US term for mountboard.
Obeche
A fine grained hardwood commonly used to make picture frame mouldings. Obeche is soft and is relatively cheap. It is ideal for painted finishes, though basecoats are needed as the surface is highly absorbent.
Ultra-violet (UV) light
The invisible light at the violet end of the spectrum that causes paper to deteriorate and discolour, as well as fading some colour pigments. UV light is a major threat to the longevity of works on paper.