recording watermarks

[Virginia Tech]

Dear L.Finch: Recording watermarks is for most of us a matter of budget. 
 Since I am not in the rank of betarays or similar, I had to look for a  
 more unexpensive procedure. My son helped me in developing it. I use a  
 special portable screen(Cold Cathod Fluorescent tube backlight; weight  
 400 grams;measurements:205x155x17 milimeters) and a digital camera. I 
than store the picture into the computer, enhance the image and try to   
 compare it with existing watermarks archives and other sources(Not al-  
 ways with success). An even less expensive way and useful in case that  
 the document cannot be lightened from underneath, is to make a rubber-  
 copy, using tracing paper and a very soft pencil(5B to 7B),and fixing   
 the image with a spray. This procedure has to be practiced previously   
 to avoid any damage to the documents. The spraying has to be done out-  
 side the storing area of the documents. Such reproduction can be easily 
 filed together with the reference and data sheet. Both procedures have  
 the advantage to reproduce the watermarks in the exact shape.           
    Manufacturing of color paper in 1750 is well described in La Lande   
 "The art of making paper" I have only a fascimile (1968) of the spanish 
 translation dated 1778, which is easily available. On the other hand,   
 since manufactured color paper was usually a low grade product, most do 
 not show watermarks or only initials. A good reference of the subject   
 colorpaper, including identification procedures, can be found in: Weiss 
 Karl Theodor "Handbuch der Wasserzeichenkunde" Leipzig 1962,p.65 -68 and 
 p.227 to 229.My best wishes in your research,Tomas Stohr.