[Scriptoris] Vegetable Parchment question

[Diane Rudin]

The process of making vegetable parchment involves treating the vegetable pulp with sulfuric acid.  The resultant paper is not archival quality, and will darken and become brittle with age, noticeably deteriorating within 20 years.  In addition, pH-reactive colorants (most noticeably turnsole, but also madder and most other organic dyestuffs) will be affected by the acid paper, discoloring or even fading from sight.

When I first started doing originals, I used Strathmore Bristol Board paper.  Those pieces are beginning to yellow with age.  I moved to using Arches 140# Hot Press paper for originals, and those pieces are *not* yellowing with age.  So, not even all fine art papers are created equally age-resistant.

Some papers come with a label "acid-free".  "Acid-free" is not 
synonymous with "pH-neutral".  The best way to check a paper's chemical 
stability is to test it with a pH-indicator pen.

Of course, the absolute best surface for C&I, from a longevity point of view, is real vellum/parchment made from animal hides, but that's expensive ($100/side), and some people also have moral objections to its use.

If you're doing work that you do not intend to remain in good condition for the lifetime of the recipient, use whatever you like.  But for archival work, it really is best to use archival materials.

--Serena



----- Original Message ----
> From: "jwtopp at peoplepc.com" <jwtopp at peoplepc.com>
> To: scribes-bounces at antir.sca.org; "Scribes within Ansteorra - SCA, Inc." <scriptoris at lists.ansteorra.org>; MK-SCRIBES at yahoogroups.com
> Sent: Wed, May 12, 2010 6:06:17 PM
> Subject: [Scriptoris] Vegetable Parchment question
> 
> Mistress Serena says that vegetable parchment is chemically unstable.  
> How
so?  I love the fake parchment I received as a gift when in the 
> Mid-realm.
I really need to know how unstable it it .  Thank 
> you

Janie Topp

Lady Maeve Dianotto