Friday, 30 September 2016

Greasy Fingers

In 2014 I wrote about wargamers who think their matt varnished figures acquire a shine because the varnish has worn off during play.  In the article “The Unvarnished Truth” I was at pains to point out that this was far more likely to be due to the deposition of sebum adding a nice glossy layer to the figures.

Earlier this week I came across an article from the British Library discussing their policy on using gloves to handle their more precious items.  It provided the following which may be of interest:
“A widely referenced paper, in the conservation field, and several forensic references, refer to fingerprint deposits consisting of 'over 98% water'. Recent analytical and theoretical studies of latent fingerprints, demonstrate that this figure is substantially in error. The deposit from a single human finger touch, whilst varying widely between individuals, is likely to contain less than 20% water and on average be about four micrograms of a mixture of amino acids, salts, primarily sodium and potassium chloride, fatty acids, squalene and many other trace compounds.”
This part of the article is from the well respected fingerprint expert Terry Kent, who I met when he worked for the Police Scientific Development Branch, he goes on:
“There are other potentially negative effects of fingerprint deposits from a conservation standpoint; again not well researched, these include the effects of microbial or bacteriological activity on such deposits. There is also the potential of the deposit to attract and retain dust and other material from the environment.

The protective effect of hand washing, standard practice for many institutions and effective for the removal of transferred dirt, is less effective for the secretions which lead to fingerprints - it has been shown recently to be negated by natural replenishment of secretions in as little as five to ten minutes. So we need to consider the likely impact of these deposits on various substrates.”
The last point about hand washing is scary: even with clean hands your figures are going to get shiny!

2 comments :

  1. Not with mine as I use 2mm deep MDF bases and cover the entire underneath with commercial magnetic sheeting which means my bases are at least 3mm thick so can be used to pick up the figures instead of touching them as often.

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    Replies
    1. "Not with mine" is absolute whilst "touching them as often" is not absolute. I've no doubt the thick bases help reduce touching but I doubt they prevent it altogether. It's only a matter of time and usage.

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