I concur with Mary.  The first thing to do is to control the humidity in the rooms, since the psocids feed on mold.  Otherwise, the pests will continue to exist - not only in the drapes - wherever there is a source of nourishment.  External walls are difficult in these situations.  It is unlikely that the fabric will be harmed by the pests.  Anoxia is the preferred treatment.  The heat may cause some physical and chemical changes in the viscose/rayon, but it will probably not be significant.  

David Walker

Walker Textile Conservation
www.talismanrestoration.com


On Oct 9, 2012, at 9:29 AM, Scottish Conservation Studio wrote:

> Hi there,
> 
> Lynsey Haworth from Historic Scotland would appreciate help with the following: 'At one of our properties we have several sets of drapes on walls.  They are made from viscose chenille, gold thread and cotton. There had been lots of rumours about there being a pest problem within the drapes, and a pest control company did some investigation and found there to be booklice in the drapes, believed to be caused by the damp environment. The proposed treatment that they have suggested is a heat treatment, where the drapes are heated in a pod to between 54 and 60 degrees Celsius for approximately one hour, which will kill the booklice and any microscopic mould they may be living off of. The humidity is monitored during this process and the temperature can be adjusted to ensure that the drapes are not put at risk.
> 
> Could anyone tell me if they have used a similar method for treating a pest problem before? How safe is it to textiles?  I should note that the drapes are not historical. They are only about 13 years old, but were commissioned especially so are quite expensive and we do not want to risk them being damaged. If anyone can offer any advice or insight into this proposed method of treatment I would be very grateful.
> 
> 
> Lynsey Haworth | Regional Collections Manager (Central)
> __________________________________________________
> Historic Scotland | Alba Aosmhor
> Longmore House, Salisbury Place, Edinburgh, EH9 1SH
> t: 0131 668 8641   m| 07794 045801
> e: [log in to unmask]
> www.historic-scotland.gov.uk'
> 
> 
> If you can help Lynsey, please send your reply directly to her e-mail address.
> 
> Many thanks,
> Tuula Pardoe
> Accredited Conservator of Costume and Textiles
> -- 
> The Scottish Conservation Studio LLP
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