Triple mount

A selection of mounts are being cut in the photo at the top, which were then used to make the triple layered mounts seen above. The inner mount is an extra thick (2000 micron compared to the usual 1500 micron) dull white museum board, in the middle is a dark grey with black core, and the top or outer mount is a solid coloured core museum board with a debossed line.

Double Double Thick

Mountboard comes in various thicknesses, the standard and most common being between 1.4 and 1.5mm, but there are also boards available at (for example): 2mm, 2.2mm, 3mm, 3.5mm and the thickest at 4.1mm which is only available in white.

As with jumbo (large external) sized boards the colour choice decreases as the thickness increases. I find the metric measurement of mountboard thickness easy to understand, some suppliers use another system where the thickness is measured in 'ply', so 4 ply is the standard (1.5mm?) and 8 ply is double thick (3mm?).

I use a range of museum mountboards which have a solid colour throughout, they come in about 50 colours at 1.5mm, with about 6 colours at 3mm thick. Because the core is a solid colour you can easily laminate two 1.5mm boards together to give a good range of colours at 3mm thick. In the photos above I am laminating two 3mm thick boards together to give a monster 6mm thick piece of mountboard.

I mixed up some wheat starch paste and used a roller to spread over the board, put the boards together (cut at 24" x 32" which was slightly oversize so they could be cut to size after gluing) and weighted down with sheets of glass.
After a day the board was cut to size and then the bevelled aperture was cut on the mount cutter, I guess if you have a CMC (computerised mount cutter) then this thickness of board would be a doddle to cut, but with a manual cutter it takes a little bit of calibrating and fiddling about. You can see the mount cutter blade has had a small section removed to allow it to cut through fully, in this photo you can also see a test mount which was made from two different colours of board. Cutting was done at two depth increments as the blade was flexing too much in one cut. In the last photo you can see the finished result - a double double thick mount with a very big bevel.

Poor quality tapes can damage art!

This is not what you want to see when you take apart any frame, let alone a drawing by L.S. Lowry. Self adhesive tapes such as seen here (yellow/brown masking tape and parcel tape) should not be used inside framing, and should NEVER come into contact with the art. You can see in the second photo where the adhesive in the parcel tape has dried out and left a nasty residue.