It is very important to use acid free paper and materials for the mounting. Otherwise the paper might embrittle as a result from acid decay within the paper and might contaminate the pastel painting as well.
I have found a company who has a lot of knowledge in these fields and whose slogan is: »Preserving cultural assets for the next generation.«
Furthermore they provide excellent craft when it comes to cutting the edges.
© Astrid Volquardsen 2014
© Astrid Volquardsen 2014