How to mount an artwork
As a qualified, experience professional picture framer and Fine Art Trade Guild Accredited picture framing course provider, I can tell you that most art work on paper is mounted incorrectly. When I say incorrectly I mean either in a way that will cause the art work to wrinkle or distort, or using mount boards and tapes, that will cause acidic damage or adhesive staining, or which are irremovable. In most cases this is due to ignorance; whoever mounted the artwork simply didn’t know how to do it in the right way, using the right materials. I have seen very valuable artworks, mounted by reputable framers which have been mounted using irreversible techniques and damaging materials. Correct mounting is a major aspect of conservation framing and costs little more in terms of time and materials.
How not to mount art on paper.
Paper expands and contracts with humidity. When you mount paper it is important to restrict this expansion as little as possible. The more you limited the fluctuation of the paper the more likely the paper is to wrinkle or distort. This is known as cockling and buckling. To reduce the chances of a mounted piece of artwork cockling or buckling don’t attach it to a mount by either taping it or adhering it along the top edge, by all four corners or all the way around the picture.
What is the best type of mountboard to use to mount art on paper?
This may come as a but some product descriptions can be misleading. Picture framing tapes and board products are a good example. These can be described as ‘acid free’ or ‘pH neutral’ but, in actual fact, become acidic over time. For example, board products made from un-purified wood pulp, such a standard, cream core and whitecore mountboards, contain lignin. As lignin breaks down it becomes acidic. Hence a mountboard that was ‘acid free’ at the time of production isn’t acid free a numbers of years later. ‘So what?’ you might say. The problem is that acidity believes that sharing is caring and migrates from one item to another. This means that mountboards and backing boards that touch art work will leach their acidity into that artwork. This leaves the art work weak and brittle and causes brown staining.
Look at a picture that was framed twenty or thirty years ago and you’re likely to see that the once white mount bevels have become brown. You may also notice that the paper close to those bevels has also discoloured. That brown colouration on the mount bevels and artwork is acid damage, caused by the lignin in the mountboard. Similar damage occurs when the board behind the artwork contains lignin.
These days’ reputable suppliers in the UK adhere to the Fine Art Trade Guild’s Mountboard Quality Standards. Look out for the Guild’s logo and confirmation of compliance on supplier’s promotional literature. There are a number of factors that go into categorising mountboard in the Guild’s four levels of quality, including light fastness, lignin content and whether or not optical brightening agents can be used. However, to give a brief summary: Level four board aka Standard or Cream Core is only suitable for art that requires no long term protection. I read that as ‘can start to damage artwork quite quickly’. Level Three board aka Whitecore is suitable for artwork that requires no more than 5 years protection. Level Two board aka Conservation is suitable for art that requires 20 years protection and Level One board aka Museum, Cotton, Rag, for art that requires 35 plus years of protection.
Please bear in mind two things: 1. this is a simplified outline of the aspects of the Fine Art Trade Guild’s Mountboard Quality Standards and it only covers the acidity of mountboards. 2. There are other factors that make mountboard suitable or not suitable for conservation level framing. Check out the Guild’s website for more info: www.fineart.co.uk. I also cover the Guild’s mountboard quality standards as part of many of my picture framing training courses.
What type of tape should I use to mount art on paper?
There a lots of types of tape that you could use to attach a picture to a mount, depending on how well you want to protect the picture and how long you’d like the picture to stay in position. However, I’m trying to promote good practice here. When mounting artwork avoid tapes that are self-adhesive. The adhesion will eventually fail. Sometimes quite quickly. Self-adhesive tape can also stain artwork and some are impossible to remove without using the skilled but costly services of a paper conservator. In most circumstances, the best tape to use to attach your picture to its mount is conservation gummed white paper tape. This is available from all reputable framing suppliers. Gummed paper tape won’t adhere to some photographic papers which can react badly to even the slight amount of moisture required for using water activated gummed tape. If that’s the case you’ll either need to use a different mounting technique, or use a self-adhesive tape and accept that it may not hold the photograph in position for as long as a gummed paper tape would.
How to mount art, pictures and photographs on paper.
When paper based art is mounted to a high standard the mount itself will consist of a number of components: a window mount, an under mount, the tape that hinges them together and the tape that hinges the artwork to the undermount. This is known as a mount package. A window mount protects artwork by creating ‘air space’ between the artwork and a frame’s glazing. This is important for two reasons: 1. Moisture can develop on the inside of the glazing due to external temperature changes. You don’t want this moisture coming into contact with the art work. 2. Some photographic papers stick to glass. Once stuck they are irremovable.
An undermount protects artwork from impurities in the frame’s backing board. Like mountboards, backing boards are often marketed as pH neutral but contain lignin. The simplest thing to do is make an undermount of the same mountboard as the window mount, as the two should be of the same quality and a minimum of 1.1mm thick. In mountboard terminology that’s 11,000 microns thick. Be cautious of using dark mount colours for undermounts, which may show through the artwork and alter its look.
The components of a mount package: A window mount, an undermount, hinging tape & artwork.
Cutting a window mount.
When you cut a window mount you need two measurements: 1. The window aperture size. Which is normally 5mm smaller, horizontally and vertically, than the artwork. This is so that the mount borders slightly over lap the artwork. This overlap can be decreased slightly on very small pictures and increased on larger pictures. 2. The overall size (aka glass size) which consists of the window aperture width plus the width of the left and right mount borders, and the window aperture height plus the top and bottom mount borders.
How to make a mount package.
To make a mount package you will need to hinge the the window mount and under mount together. This is done by joining the two using the white gummed conservation paper tape, mentioned above. The join should be along the longest edge: the top on a landscape mount where the mount is wider than it is high, and the left hand side on a portrait mount that is higher than it is long. Why the left hand side? I’m really not sure. It’s traditional and, quite frankly, there are some questions that are not worth asking. I can only speculate that it is because the majority of peopled are right handed and therefore will find a mount package that is hinged on the left side easier to open.
To hinge the window to the under mount place both mounts next to one another, window mount face down and under mount face up, so that the sides to be joined are aligned and touching. A length of gummed conservation tape should be cut to the same approximate length as the join, dampened with deionised water and place along the join. It may help to place paper weights on the two mounts to hold them in position. Gummed linen tape can also be used to hinge the window mount to the under mount but I find the paper tape easier. Give the tape a couple of minutes to dry before folding the two mounts together, like a book. Align the window and under mounts then apply a little pressure along the join so that the mount package opens and closes in alignment.
The window mount is hinged to the under mount along the longest side.
How to attach a picture to a mount.
Now that you have made a mount package, the artwork should be attached to the under mount, not the window mount. It’s common to see art attached to the back of the window mount. This is poor practice born from either ignorance or the desire to save the cost of an undermount. When artwork is attached to the back of the window mount it isn’t supported properly and flaps about as the mount is handled during the framing process. This can damage the artwork, particularly around the edges as they come into contact with the sharper, harder edges of the bevel cut window mount.
The standard way of attaching paper based artwork to the undermount is using T-hinges. Each T-hinge is made up of two pieces of tape, an upright and a cross piece. In most cases the conservation gummed white paper tape, mentioned above, is ideal for this.
Cut the upright piece of tape at least 5mm longer than it is wide (normally the width of the tape) and the cross piece at least three times longer than the width of the tape. Dampen approximately 5mm of the gummed side of the end of an ‘upright’ piece of tape, using deionised water, and place it on the underside of the top edge of the artwork, around a quarter of the way in from the side. The upright should overlap the top edge of the artwork by around 5mm, depending on the size of the art work and the weight of paper it is on. If the artwork is bigger than A4, you may want to increase the overlap, or even the number of hinges. If it is smaller than A4 you may want to decrease the overlap slightly or decrease the width of the upright. A minimum of two T-hinges should be used. You may also wish to weigh down the T-hinges with paperweights as they dry.
The uprights of the ‘T’ hinges attached to the back of the artwork.
Allow a couple of minutes for the uprights to dry, then place the artwork into the mount package, between the window and undermount. Gently move it around so it sits in the position you require under the aperture of the window mount. Remember to make sure that the mount overlaps the artwork on all sides. Once you’re happy with the placement of the artwork, hold it in position with a paperweight. Warning: Some photographic paper damages very easily. So avoid the putting a paper weight, or anything else, on it. The same applies to artwork with fragile or migratory pigments, such as pastels, charcoals and the like. This type of artwork can be damaged very easily and also requires much more air space between the art and glazing.
Next, dampen the glossy side on the pre-cut crosspieces of gummed tape and place them over the upright part of the T-hinge. To allow for paper expansion, as mentioned earlier, they should be positioned with a few millimetres of gap between them and the top of the artwork. You may also wish to weigh down the cross pieces as they dry. Give the cross pieces a couple of minutes to dry before closing the mount package.
The artwork hinged in to the mount package with T-hinges.
The finished article ready for framing.
If you would like to learn how to cut a range of mounts and mount different types of art work to a professional standard, including conservation standard mounting, check out our mount cutting course and other UK based picture framing courses.