First, I think it is important that we make a clear difference between the passe-partout or mount and the Marie-Louise or frame-liner.
The passe-partout, or mount/mat, serves to protect the artwork from the glass. It consists of a piece of cardboard the size of the glass, in which a window will be cut, often with slanted edges at 45°, to the size of the painting. The mount is then placed on top of the picture, between the image and the glass.
The passe-partout can be used to make a picture occupy more space once framed.
The passe-partout comes in many colours and textures and will often be used as a decorative element, to add a personal touch to the artwork.
The Marie-Louise, or frame-liner, is a more ancient term, it consists of an intermediary frame which is placed between the canvas and the
Now that we have cleared the air, let us talk about the framing mount or passe-partout.
What can a mat / mount do for my art?
A mount’s main purpose will be to protect your art from touching the glass. The passe-partout is therefore used when framing watercolours, lithographies, pencil, pastels…
But why shouldn’t your art touch the glass of the frame?
- Changing levels of humidity in a room can cause condensation to form on the glass inside the frame. The moisture will then seep into the paper that is pressed against the glass. This will discolour your art and could cause your art to stick to the glass as the moisture dries. This adhesion can also happen if the media of the original piece is soft or tacky.
- We all know that glass transfers heat very efficiently, so having your artwork pressed against the glass makes it more likely to buckle or warp as you’ll likely get a sharp change of temperature between the front and back of your frame.
Mounts come in a wide range of colours and you can use your mount to accentuate components in your art. It is, however, safest to keep the colour of your passe-partout sober as you will not want to detract the eye from your artwork.
A coloured passe-partout should complement the artwork.
Note that the board used to make your mount must always be acid-free and cotton based. Why? Because wood pulp based boards aren’t as durable and can turn your artwork’s paper yellow with time.
The width of the passe-partout, or mount/mat, is your choice, and it is always best to stay on the wide side as a thin passe-partout will not let your art breathe. A wider passe-partout, on the other hand, enables you to give more importance to your art.
Of course, the mount works for framed art mainly, but you could use the passe-partout to “frame” unframed art. Take a look at our article on how to hang unframed art for more inspiration.