I recently encountered a short written history of dry mounting and noticed an interesting parallel between the history of handling photographs and that of digital prints and fine art of today. In order to better compare them let's take a look at an abbreviated history of dry mounting in general.
Abridged History of Mounting
Whether for holding things together or for repairing little accidents of time and misfortune, there has always been a need for adhesives. From the early 1800s to 1945, adhesives included protein based (hide glue, gelatin); sugar based (dextrin); starch based (arrowroot, wheat, corn, potato, rice); vegetable or gum based (arabic…); rubber based (rubber cement); and assorted combinations of these materials. Extensive moisture was necessary when bonding any of the above adhesives which introduced expansion, stretching, cockling and/or curvatures in both photographs or paper prints. Rubber cement was least moisture inducing, but contained sulfur that discolored and often failed shortly after mounting.
In an effort to keep moisture down, a thin paper carrier was developed with thermoplastic adhesive on either side which was activated by heat. Dry mounting had arrived. The term "dry mount" was originally used to distinguish between this new dry technique from traditional damp and wet techniques of mounting. The first dry mount tissue patent was issued by the "Derepas" Brothers in France in 1901. In 1903, a British Company called the Adhesive Dry Mounting Company, Limited, received patent #17,327 "An Improved Process for Mounting Photographs, Engravings, and the like, and as a Means for Carrying the same into Practice." As stated by the British company, they had developed a material capable of mounting "…photographs, engravings, or documents of any kind, on Bristol board or cardboard…"
The Kodak Company started manufacturing dry mount tissue with what might have been the Derepas formula in 1906. And by 1915 the self proclaimed "pioneers and originators of dry mounting" the Adhesive Dry Mounting Company, Limited adopted the anagram ADEMCO for their company.
Early TTPM
The new adhesives used thin silk paper or Japanese paper as a carrier which was dipped into an alcoholic solution of shellac then dried. In 1907, recommended temperature tolerances for photograph mounting were published in The Photographic Monthly as follows:
Carbon and gum prints |
140-150ºF |
60-65ºC |
Gelatine-chlorides (strongly alumed) |
165-175ºF |
75-80ºC |
Albumen |
195ºF |
90ºC |
Platinum, plain-salted silver, and prints with matt faces no gelatine |
95-205ºF |
90-95ºC |
With very thick papers it was stated, "…these temperature may be increased a little and the time could be lengthened to 15-20 seconds for bonding." This is the first indicator of time, temperature, pressure, moisture rules (TTPM). Interesting that even with the later development of more heat tolerant resin-coated (RC) photos, suggested mounting temperatures have remained very similar even today. Note the lower temperatures suggested for carbon prints at 140-150ºF, partnered with the short dwell time of less than 15 seconds. Sounds like the low temperature, short dwell time HA boards (SpeedMount™…) that have been developed for heat sensitive digitals today.
The same article goes on to say, “…To remove a mounting, heat a metal plate to 250ºF or 300ºF (120-150ºC) and lay the print upon it, raise the corner and the whole print can be stripped without injury.“ The warmth of the highly heated metal plate beneath would penetrate the photo from behind without risking surface damage while still reactivating the adhesive for removal.
Early Equipment
Presses and irons were also developed to accommodate the new techniques and materials. The first commercial dry mount presses were advertised in 1904, and by 1906, advertisements for tacking irons, called touchers or fixing irons, began as part of the "Adhero" Dry Mounting Machine system sold by the Adhesive Dry Mounting Company.
Machines introduced in 1906 were pressure controlled by a central screw and wheel system similar to letter and book presses or clamp or lever models. These machines were initially heated by burning paraffin, oil, gas, or alcohol, but in 1907 were adapted for use with electricity. New innovation at the time, electricity. The style and design of these early presses varies little from current hardbed and softbed (mechanical press) models. Seal Products, Incorporated, founded in Connecticut, 1936, developed their first dry mount mechanical press in 1947. Heated vacuum presses did not emerge until the 1970s.
Photographs and Adhesives
Dry mounting is historically the mounting process of choice by photographers for photographs. The photographic industry standard has always been to develop materials and processes to shorten working times, often implementing higher bonding temperatures. Then, "in August 1934 Kodak introduced an improved [Type-I tissue] with better adhesion and requiring less heat" (Wilhelm 1993). Lower temperatures again being potentially less damaging to surface emulsions.
In 1941, a Kodak Chemical Plant employee, Mr. Wentworth C. Eaton, cited most dry mounts as being comprised of rubber-wax (cohesive tissues) or shellac (thermoplastic resin). Photos using a faster developing process and waterproofed print papers might melt at the higher 175-210ºF temperatures required for mounting with shellac-based dry mount tissues. In that same year, Kodak released a lower 150ºF temperature mounting tissue using a wax adhesive called, Thermount Tissue which was marketed until 1957. Kodak continued to make Type-I shellac-based dry mount tissue until February 1974 when it introduced Type-II, a synthetic adhesive.
Seal Products released their first dry mount adhesive, Foto-Flat in 1938. Specifically designed to target the lower temperature requirements of photographs it was a synthetic, removeable tissue that was impervious to moisture and unaffected by climatic temperature changes.
Low Temperatures Continue
History continued and time marched on. Numerous dry mount products have been developed by many companies. From 1938 to date we have seen tissues come and go; companies fuse; and formulations change lowering tissue bonding temperatures. Then came heat activated boards, very innovative in the early 90's. Though p-s coated boards and materials had been around, this was the first time a dry mount adhesive was preapplied directly to the mounting substrate. They were clean, easy to use, priced right, and huge time savers that were marketed for use "with posters, paper artwork, photographs, newsprint and fabrics".
Not unlike many traditional photographs, heat sensitivities have once again emerged issue with the technologies of today. For home/office inkjet printers that use thermal bubble jet technologies (most HP printers), low bonding temperatures are a must. The demand for lower temperature adhesives has been met over and over again with products bonding between 150-175ºF, including Single Step Plus and SpeedMount. Even with the above mentioned HA boards, as the mounting challenges changed from traditional RC photo to digital photo to paper based art, so has the amount of time the board must remain under heat and pressure to effectively activate and bond. Remember the chart above printed in 1907 for photo tolerances and the heat comments below it concerning variables?
Most current HA boards require from 15 seconds to 3 minutes to mount assorted items, with SpeedMount suggesting the shortest dwell time. This is an important factor with Hewlett-Packard printed digital photos or heat sensitive laser color images. Both images tolerate 150-155ºF temperatures for up to 30 seconds, but will often surface damage (even at that low temperature) with a dwell time of 1 minute or more.
Removable or Reversible?
As the industry spokesperson for mounting, I have been the voice of framers to manufacturers for almost twenty years now, always demanding more. During the 90s amidst the onslaught of the early heat sensitive digitals and dropping adhesive temperatures, my ongoing plea was for a pressure activated tissue adhesive (not pressure sensitive or PSA) that could be bonded by only the pressure in a cold frame, mechanical or heat vacuum press. They appear to still be working on that one.
But, every now and then a new mounting technique or product comes along that makes one sit up and take notice. Something that didn't fill any specific void or request. Throughout history, dry mounting as never been noted as a reversible technique, but at times merely a removable one. And no dry mount adhesive could ever be totally removed. This is true because the very heat that bonded the adhesive also encouraged absorption into the mounting, even when removed there would always remain a limited amount of adhesive in the document or artwork.
Artcare Restore™
So now we have been introduced to Artcare Restore, and why is it different? By all accounts the adhesive used with Restore is inert, pH neutral, and does not appear to leave any adhesive residue once an image has been removed. All adhesive seems to brush away. Adhesives notoriously will show up under a black light, like white fuzzes. Yes even under a black light when removed there is no white remaining, and any residue adhesive will dust off with your fingertips. Perhaps we simply need to trust the unknown.
Restore looks like any HA precoated foam board though it does have a slight tooth to the matte finish adhesive side. I have completed my own testing in relation to mounting and removing images from photo to digital to newspaper, and have decided to believe in this as a revolutionary new type of product, a new adhesive concept altogether, not unlike the dry mounting of 1906.
The Ultimate Test
I am a purist when it comes to framing my own artwork for my gallery. I only mat with 100% cotton museum boards, UV Conservation glazing, and always use preservation hinging techniques. As an artist for Wild Apple Graphics I have hundreds of originals, some published, some stored.— Since I paint with sumi inks and collage many of my images, there are numerous variations in paper weight, multiple layers and much moisture present during creation. Hence the edges warp like watercolors can.Hinging still may result in wavy edges beneath the window. Though I consider this an intricate part of the creation it has never bothered me, but clients would rather they not warp. Size all materials and prepare to mount. Notice the completed double mat has already been completed. Tack the centered artwork to hold it in place for mounting. Because of the thicker collaged layers this image required 160ºF for 1 minute to mount using release papers. The completed image now shows smooth lines at the window edge.
Dry Mounting in the 21st Century
It has been established that lower temperatures are safer for mounting. This is why the low temperature HA boards have worked so well with photographs since their release. Adhesive reformulations over the years have lowered tissue adhesive temperatures from 225ºF to that of 190ºF. Lower temperatures, less adhesive absorption, less potential for damage. Yet, any adhesive absorption is not preservation. The framing industry and conservators alike have had a tough time accepting new practices. Dry mounting a traditional canvas is wrong, while dry mounting a digital canvas is becoming the correct way to present it.
Throughout the history of dry mounting, innovations in the formulations of dry mount adhesives have evolved, first to meet the needs of photographic materials and technologies, and now same with digital photographs, prints and canvases. Photography has dictated many new products throughout the past 100 years.
In 1993, Stephanie Watkins, AIC wrote "Dry mount has been used on photographs, books, papers, textiles, and paintings in conservation treatments [throughout history], also. Therefore, questions remain and the research continues." It is now 2004 and the research continues. Museum curators are being forced to deal with large face mounted photos being placed in their collections. This is the permanent mounting of the surface of a digital print to the verso (back) side of clear acrylic for display, generally by the artist. Museums now are buying one for display, one for dark storage, times have changed. Remember the British company that developed a material capable of mounting “…photographs, engravings, or documents of any kind, on [acidic] Bristol board or cardboard...at the opening of my article? They believed in gluing things down then.
We would never consider using masking tape or corrugated cardboard to frame today, but we did at one time. Perhaps a few years from now we will think back to the days we would never consider dry mounting an original and think that sounds odd too. Now if I can only get framers to see that mounting a digital canvas is also thinking into the future we might be truly reaching into the 21st century of framing.
Today my horse wears plastic horseshoes; I send my articles via email attachment; and I mount some of my original art with Artcare Restore, who knew? So get those wrinkles out of that watercolor, and welcome to the 21st century!
END
Copyright © 2004 Chris A Paschke
Bibliography:
“Origins and Development of Dry Mounting”, paper by Stephanie Watkins, The American Institute for Conservation (AIC),1993.
MOUNTING, LAMINATING AND TEXTURING, Seal Products, Incorporated, 1990
THE PERMANENCE AND CARE OF COLOR PHOTOGRAPHY, Henry Wilhelm & Carol Brower, 1993.
For more articles on mounting basics look under the mounting section in Articles by Subject.
Additional information on all types of mounting is found in:
The Mounting and Laminating Handbook, Second Edition, 2002,
The Mounting And Laminating Handbook, Third Edition, 2008 and
Creative Mounting, Wrapping, And Laminating, 2000 will teach you everything you need to know about getting the most from your dry mount equipment and materials as an innovative frame designer.
All books are available from Designs Ink Publishing through this website.
Chris A Paschke, CPF GCF
Designs Ink
Designs Ink Publishing
785 Tucker Road, Suite G-183
Tehachapi, CA 93561
P 661-821-2188
chris@designsinkart.com