AboutDavid Silver Expertise My name is David Silver. Antique and classic cameras, vintage photographs, general photography and all areas of the history of photography are my expertise.
Experience I've been a professional photographer and a student of the history of photography for nearly 30 years. During that time my collection of vintage cameras and photographic paraphernalia has grown beyond 2000 significant pieces. I've published nearly 70 articles in the field, including 16 in the popular "Buying Classic Cameras" series for PHOTO SHOPPER MAGAZINE from 1995 to 1997, I'm currently a contributing editor for CAMERA SHOPPER MAGAZINE and McKEOWN'S PRICE GUIDE TO ANTIQUE AND CLASSIC CAMERAS, and I've written numerous entries for WORLD BOOK ENCYCLOPEDIA. Portions of my collection have been displayed in museums and special exhibits in the past two decades, and many of the items were photographed as illustrations for books. In 1985 I founded the International Photographic Historical Organization (InPHO), which eventually evolved into its intended purpose as the best first resource for information on the history of photography. I'm also a founding member of several e-mail forums dedicated to specialized areas of photography, and I'm the moderator of the Internet Directory of Camera Collectors (IDCC), which remains the largest and most successful such group in the world. For more information about the International Photographic Historical Organization and its many services, please visit its web pages at:
Question Were convex portraits from the late 19th century made wet under pressure, and is this why I see so many that are now cracked toward the center? (Even when they've been framed continuously.)
Also, is there anyone still using the process that you are aware of?
Answer Hi Chris,
No, not under "pressure". The paper they used was very thin, so when it was wet it was very easy to simply lay it across a pre-curved backing material (depending on the size and quality, it could be metal, cardboard, or even a shaved down piece of wood), and the paper automatically adhered to that surface and dried that way. However, over many years, simple physics dictates that there will be a bit of tension towards the center of the image, so we often find them with subtle radiating cracks. Even if well framed, a photograph will still react to extreme changes in humidity or temperature, and curved images in particular will react to prolonged exposure to direct sunlight. The cracks can be repaired, but the cost outweighs the value of the typical portrait. Too darn common. Better to leave it alone, and make sure it is clean and safe in its proper frame.
I'm not aware of any professional photographic services that offer this process anymore, it went out of favor in the 1930's, but amateurs still play with it. I've done it myself. You need old-fashioned single weight fiber based photographic paper (thin stuff, extremely pliable when wet), never double weight or resin coated papers, and I like to "paint" the curved surface with a very diluted white glue solution before applying the paper. You can wrap the paper around all sorts of things!
