A decision was made not to attempt to completely flatten the drawing. The aim was to reduce the upward folds enough so that the drawing could be displayed within a deep overthrow window mount. This would protect it from future abrasions and stop rubbing occurring to the surface.
After the drawing was surface cleaned, the paper was humidified to relax it and reduce the folds. Care was taken not to reactivate the adhesives used in the application of the previous repairs through over-relaxing. Once lightly humidified, the drawing was pressed lightly between felts, reducing undulations and localised cockling, which had occurred in the corners. For further details of the humidification process, see case study X/18.
Historical repairs are removed if:
they are too heavy, as is the case with patch repairs
they are causing planar distortions
heavy discolouration has occurred and glue has deteriorated
Old tears are generally more problematic for the conservator as the paper may have lost fibres, the edges may have hardened with glue and there is an increased likelihood of ingrained dirt. Unfortunately, this will mean that any new repair will still remain obvious.
Historical repairs that had caused structural damage were removed using a steam pencil and eased off the paper using a spatula. During the removal process the object was protected using a blotter: this prevented the formation of tide lines.
Historical repairs, as on the reverse left and right edges of sheet XIV/4, shown here, were not removed as although they are not a good weight or colour match, they posed no structural stresses upon the paper.
It is often essential to preserve old repairs or restorations as they hold historical significance and can hold information on the history of the drawing.