Friday, June 22, 2012

The Importance of archival materials for art and framing


The Importance of Archival Materials:  Part 2
     by Susan Avis Murphy
      Do you know what can ruin your appreciation of an artwork after a few years?    Creeping decomposition…   I have been working in the art and framing business now for about 35 years, and I could tell you some horror stories!  In the last article in this series, I told you about the flowers that faded away completely during just two years in a painting a customer told me his mother once bought!  That was an issue of lightfastness of the pigments (link to article on lightfastness).   This article is going to be about the integrity of the materials the paint is put on and the framing materials that surround the painting.
     “Creeping decomposition” sounds creepy, doesn’t it?  Decay of a painting and its framing can start occurring immediately and become apparent in about five years.  What are the chief culprits and monsters of this decrepit situation?
·      Acid.  Acid found naturally in wood pulp materials, such as cheaper art papers and cheap matboard, will eventually cause those materials to become yellow and brittle.
·      Mold.  Mold present before framing can grow and spot the surfaces if the picture is stored in a humid environment.
·      Insects.  Tiny insects such as spider mites like to creep into narrow spaces and eventually stain the surface of the mat and picture.
·      Pollution.  Especially smoke, such as cigarette smoke will eventually dirty the surface of an exposed oil or acrylic painting
·      Dirt.  Dirt can somehow get under the glass of a painting—hard to believe but true!
·      Humidity.  Humidity is one of the main culprits and can cause warping and buckling of the painted surface and mat.
·      Heat and dryness.  Heat and excessive dryness can cause the glue to fail in the joints of the frame.  Ever see a frame whose corners are coming apart?  The glue has failed and hopefully the frame is hanging together by virtue of its joining hardware!
     Let’s take these monsters one at a time and see how they can be defeated!  In this article we will discuss acid, and in future articles we will tackle the other creeps!
·      Acid
o    Acid found naturally in wood pulp materials, such as cheaper art papers and cheap matboard, will eventually cause those materials to become yellow and brittle.  Works of art done on paper are very vulnerable to this if the paper is made of wood pulp, such as cheap drawing papers (newsprint used for practice, for example) and cheap watercolor paper.  Paintings and drawings done early in an artist’s career are often on these surfaces.  Not much can be done for these papers after the fact.  There is a product called “Archival Mist” that is sold, and purportedly can stop the effects of acid (it contains an alkaline buffer).  It is very expensive and I don’t know how well it works, but am doubtful.  The best paper for art is “rag” paper, made from 100% cotton (I suppose it used to be rags!).  This contains no acid and should last for hundreds of years under good conservation framing.  All the better and best drawing and watercolor papers are rag papers.  I use mostly Arches watercolor paper, which has a 400 year history and is extremely durable.
o    As for matboard, this is another problem in preserving the integrity of the artwork.  Cheap, “decorator” matboard is a hazard to your artwork because acid from the matboard can creep into the edge of the art.  These matboards are made from wood pulp that has been neutralized with a calcium carbonate buffer, but eventally the effect of the buffer wears off.  Better to use either “alpha cellulose” matboard or rag mat board.  Alpha cellulose mat board is made from virgin alpha cellulose wood pulp that has been chemically treated to remove all traces of acid and lignins.  Bainbridge Artcare® and Cresent Select® are two brands of alpha cellulose matboard.
o    Backing board can create even worse problems than matboard!  Plain cardboard or Masonite should never be placed behind an artwork permanently!  These materials are very acidic and acid will leach into the paper artwork, eventually discoloring it and making it so brittle it can crumble.  The best practice is to use acid-free foamcore board behind an artwork.
Here are some photographs of a painting we recently re-framed here at ARThouse.  I show you these as an example of the terrible damage acid can do to framing.  Luckily the painting was done on a decent piece of rag watercolor paper, so it remained intact, although was someone discolored.  The painting and framing was done in 1960.
Figure 1 shows the 50 year old watercolor with its original mat.  The glass was incredibly dirty and had been removed before this photo was taken.  The glass was a heavy window-type glass and had to be discarded.   Here you can see the yellowing and acid burn of the matboard.  The inside edges had turned dark brown (a sure sign of acidity).  The matboard was brittle and crumbling by this time.
Figure 1
 Figure 2  shows the back side with its paper dust cover and brown package tape crumbling away.  The tape flaked off, but the gray paper wasn’t too bad.  Today we would use an acid free backing paper so that it retains its integrity and is less likely to rip or puncture with time. 
Figure 2
 Figure 3  shows the corrugated cardboard backing board that had been used behind the artwork.  Wow, we certainly would never do this today!!  Corrugated cardboard is a terribly acidic material.  Today we would use an acid-free foam core board.  Probably some of the discoloration of the mat and painting was due to this cardboard.
Figure 3
  Figure 4  shows the painting as it is taped into the back of the mat.  Here we see a lot of “no-no’s”.  The painting has been taped all the way around, which is a bad idea because it does not allow for expansion and contraction of the paper artwork due to humidity changes.  It is a better practice to tape it only at the top.  Secondly the tape was extremely brittle and flaked off because, although plastic, it was not acid-free.  Today we would use either linen tape or an archival acid-free plastic framers tape.  
Figure 4
Figure 5 shows the back of the watercolor after it had been taken away from the acidic matboard.  The remaining tape is mainly just the glue part—the black plastic crumbled to dust…  Luckily the painting itself was still in pretty good shape. 
Figure 5
 Figure 6 shows the front of the painting.  You can see the acid burn from the matboard all around the edges.  The painting itself may have darkened with age and the colors may have changed.  It was not protected with UV glass, so the old pigments used in the 1960’s may have been vulnerable to fading or darkening if the color was not lightfast.  Standards in pigments have improved greatly, but artists still need to be careful to choose only lightfast colors. 
Figure 6

Figure 7 shows the final re-framed painting.  We cut a new double mat using Bainbridge Artcare alpha cellulose matboard and an acid-free foam core backing board.  Also, the frame was reused because it was a unique hand-made frame still in good condition.  However the corners were coming apart because the glue had failed after 50 years, so we re-glued it and joined it with v-nails.  It should now last for at least 100 years, I would say. 
Figure 7
      The painting has not been put under glass yet, but I would recommend Museum glass for this historical original artwork because it is valued by the owner.  Museum Glass® by TruVue is both a UV-protective glass and an anti-reflective glass, and would enhance the painting tremendously.
     The owner was extremely pleased with these improvements!  Thank you, Carl, for allowing me to show these pictures.
     I am pleased to help make you aware of these issues, and would be happy to answer any questions you have.  Please send me an email at susan@susanavismurphy.com.  Meanwhile, here's hoping your paintings never undergo creeping decomposition!  And that your children and heirs will be always be able to enjoy the paintings you bought or created when you were younger...

      Susan Murphy, ARThouse, June 13, 2012 

      [article copyrighted, contact author for permission to reproduce]


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