Paper Conservation | Wet Repairs

For a while I have been trying to think of something I could do on a weekly basis to keep my blog up and running and relevant, so I thought I might do a series of instructions. These will be to let people know exactly what I am learning at the moment, It will also help me remember everything I am learning, and means I have notes for myself in the future!

So this week I am starting on wet paper repairs, as this is something I am working on at the moment and have had recent instruction in.
Prior to using the wet repair method, it is necessary to check that the object will not be effected by water, as it may have fugitive media on it or the water may cause tidelines, so relevant tests and humidification must be done first.

Repair material

A key issue in paper repair, is that the material you use for the repairs should be lighter in weight than the paper being conserved, this is because a heavier repair will create a weak spot, so if any pressure is put on the object will cause a break at the point where the two materials meet. Check the wet using a micrometer (if there is one to hand!!)

Japanese tissues, such as Spider and Tengujo are very good for paper conservation. They are archival papers and have an alkali reserve within them, which will lower any acidity in the object. They are also made from very thin, very long fibres. This means that they can often be invisible on the repair due to their weight, but strong at the same time and will provide support for the object where necessary.

Cutting the tissue and paper

Paper fibres are essential to the repairs, you cannot just cut the repair tissue or paper with a blade, as the harsh line will lift up from the object after time, you need a frayed edge of fibres to adhere properly. This is done using a water pen or a paint brush and water. You must draw a line using water onto the tissue or paper where you want to cut, you can then tear the tissue along this line, giving you a soft edge that will adhere better. When cutting infills, it is done in the same way – you can put the object on a light box with a piece of melinex on top to protect it, you can then trace an accurate line with a water pen directly onto the repair tissue/paper on top of the object and then tear it.

Mending tears

1. When repairing tears on the object, primarily, the tear must be tacked together using a small bit of wheat starch paste, this is done with a very small overlap as it will pull apart when it dries.
2. Starting out on the reverse (verso), draw out and cut a small piece of tissue using the lightbox method described above. For any tear bigger than an inch, it is better to use small pieces of tissue, letting each one dry before applying the next, as longer pieces can cause the object to cockle.
3. Trim the extra long fibres using scissors, as then will be too long to pick up the paste.
4. Paste the small piece of tissue on a piece of scrap melinex, leaving a tiny area at the end to allow you to pick it up.
5. Lift the tissue from the melinex and place onto object, and flatten down using a bonefolder on top of bondina and archival blotter, then weigh it down for a couple of minutes.
6. Repeat this process on  front (recto).
7. Once dry, trim any excess tissue from the edge of the object.

Mending missing pieces
This is very similar to mending tears, but uses an additional infill piece of paper

1. Find an infill piece of similar but lighter paper, if the object is antique laid paper, it should be repaired with the same type of paper. If it is a modern paper, it will be heavily sized, so should be put in bath of hot water to remove any size, and dried and pressed appropriately.
2. Cut the repair paper to fit the missing section using the lightbox method described above.
3. Tack the new infill piece to the object using wheat starch paste.
4. When dry, cut a piece of tissue that will cover the back of the infill and about 3/4mm of the object itself, this is because the tacking of the object alone will not be enough to keep the infill there.
5. Paste this piece of tissue to the object and infill on the verso and allow to dry under a weight, blotter and bondina.
6. Once dry check whether another piece of tissue is needed on the front – ideally not, but it may be necessary.

Please be aware these are not official instructions and should not be followed as or in replacement of professional instruction.