Adhesives for paper conservation
This one-day course, held at Tate Britain on 23rd March 2015, was tutored by Velson Horie, Collection Care and Conservation Consultant (www.horie.co.uk). It was divided into two main parts: theoretical in the morning and practical in the afternoon. The participants were 16 conservators mainly from book and paper conservation backgrounds, from both institutions and private practice.
In the morning Velson went through his PowerPoint presentations, starting with an overview of the objects to be treated and the materials added during treatments, criteria for choosing, reversibility, and polymers and their properties (molecular weight, glass transition temperature, chemical interaction and reactivity, mechanical strength and optical properties).
Before the lunch break, Velson talked about carbohydrate polymers: polyvinyl acetate, polyvinyl alcohol, etc., in which solvent they dissolve (including water), how they age and how to reverse treatments. He emphasised the importance of not keeping materials beyond their shelf life, and of testing substances – every single time – before using them on the objects we are treating because, as we know, commercial products can be unpredictable due to storage conditions, changes in manufacturer specifications, etc.
In the afternoon we moved to the Paper Conservation Studio, very kindly made available by the Tate Britain conservation staff, to go through seven practical activities organised by Velson for us to carry out in groups:
- Gloss measurement and colour change
- Starch solutions
- Testing the viscosity of solutions: ‘Falling ball’
- Testing the viscosity of solutions: ‘Rotating viscometer’
- Shrinkage on setting
- pH of liquid/solid material
- Strength of an adhesive
At the end of each activity, the groups presented their findings to the other course participants, explaining what was learnt from each activity, and how we can use those learnings in our day-to-day conservation practice. It was a very enjoyable and well-planned course, and I am glad I had the chance to attend it.
Stefania Signorello ACR, Conservator, The Wellcome Library