[NHCOLL-L:1093] Re: Light damage to taxidermy mounts.

[Robert Waller]

Jill,
I think there are two reasons for a lack of responses.  One is that there is little hard data to go on and the other is that there is considerable variability among specimens making general recommendations difficult.  Still I will answer yours question in several parts.

1) Visible light causes damage much the same as UV radiation or as a blend of visible light and UV.  Filtering the UV from light sources will result in a reduction in rate of fading in the range of 10 to 60%.  Assuming a reduction of about 30% in the rate of fading, as a result of UV filtering, is  reasonable in most cases.

2) Most furs are thought to be moderately sensitive to light - equivalent to an ISO Blue Wool 4 to 6.  To err on the conservative side, we consider them equivalent to an ISO Blue Wool 4.  This means that a perceptible fade will occur with about 50 mega lux hours (Mlux h).  This is equivalent to a few years in a bright room (windows, but not direct sunlight = 5000 lux), or to about one hundred years at 150 lux.  We specify 150lux and UV less than 75 micro watts per lumen as the maximum light and UV levels in our exhibits.  

3)  In practice, what constitutes unacceptable extents of light damage to taxidermied specimens is often uneven fading that causes the top surfaces, highlighted shoulders, etc. to be noticeably faded in relation to the rest of the specimen.  Consequently, it is most important that bright spots in the illumination of specimens be avoided.  The general light level is important, but the elimination of intense areas of lighting on specimens is most important.

Hope this helps,
Rob

Robert Waller
Chief, Conservation
Canadian Museum of Nature
Box 3443, Station D
Ottawa, Ontario
K1P 6P4
CANADA

phone:(613)566-4797
fax:     (613)364-4027
email: rwaller at mus-nature.ca 
WEB: www.nature.ca 
_____________
Rob,

No, I didn't get any responses.  Do you have any insight?  Or, were you
wanting feedback?  I was thinking of sending the message again, but didn't
know if it would make a difference.  In my exerience it is a topic that not
many people know much about.

Jill

----- Original Message -----
From: "Robert Waller" <RWALLER at MUS-NATURE.CA>
To: <jillharr at VMNH.ORG>
Sent: Wednesday, July 11, 2001 4:33 PM
Subject: Re: [NHCOLL-L:1081] Light damage to taxidermy mounts.


> Jill,
> Did you get a response to this question which came while I was away?
> Rob
>

I know UV light can cause fading of fur on taxidermy mounts.  Does anyone
out there know if visible light causes any type of damage?

We are trying to set specifications for acceptable light levels in a
travelling exhibit.  Are there general guidelines for UV and visible light
levels for taxidermy mounts?

Any help, and/or sources would be appreciated.  Thanks,
Jill K. Harris
Registrar
Virginia Museum of Natural History