Friday, January 7, 2011

Repairing Pitted Giclée Surface Coatings

Fast Fix for Warts and Craters Marring Giclée Surfaces

© Douglas Mesney 2011
Giclée surface damage is the pits.
Eventually one of your giclées will get pitted. The surface will get pulled away taking the inks with it and leaving a little pot hole in your print. It might be intentional or accidental.

Varnish is the number one cause for pitting and surface ripping. The problem is that varnish never really dries. If two varnished surfaces come into contact they start to bond together. When you separate them, one side will let go, pulling away the giclée surface. Actually, it's the bond between the ground and the substrate that is letting go.

Grounds are surfaces applied to papers and canvases used for printing giclées. The ground is formulated to accept giclée inks, which are suspensions of pigment in water and glycerin.

Glycerin is a sticky substance that is deliquescent, that is it absorbs water as does salt. The water content of glycerin is a constant 30% as a result of its deliquescent properties. Glycerin never dries because of that water trapped inside by chemical bonding. Instead, glycerin percolates into the ground medium.

Percolation is what happens when you make drip coffee... water percolates through the grounds, dripping into the pot. If you used too little water, it would percolate into the grounds but not all the way through. That is what is happening on the giclée surface.

  • Water evaporates up off the ground
  • Glycerin percolates down into the ground
  • Pigment remains lying on the surface of the ground
Giclée prints are fragile because the color is lying on the surface of the print and can easily be damaged by abrasion or air pollution. Thus they are normally coated. Although the coating seals the giclée, its bond to the surface is as good as the bond between the ground and the substrate (paper or canvas).

As mentioned, varnished surfaces stick together when they come into contact and when you separate them one will pull the surface off the other wherever there was contact. Rubber-tipped clamps, a favorite for hanging prints, also bond with varnish as do some other painted surfaces. For those and other reasons we switched from varnish to liquid laminates last year.

Liquid laminates are plastics that cure instead of drying. They don't stick together but if some bits of flotsam get trapped inside the dried coating, removing them will leave pits that need repair.

In addition there are other circumstances making it desirable to intentionally pit the surface to correct problems considered worse ...Huh?

Intentional Pitting

It may sound crazy but sometimes you need to create one kind of damage to fix another, and this is one of those. For example, you will eventually encounter surface blemishes caused by canvas tufts and/or bits or crap caught in the coating.

Canvas tufts are imperfections in the weave that cause a little lump. The lump becomes more apparent when the giclée is coated.

'Jellyfish' are another problem. They are what I call semi-congealed bits of the coating. Small ones can be hard to see when the coating is wet and milky, but their lumpy profile is easy to see when the coating hardens and clarifies into 'warts'. But by then it is too late.

To fix problems like those I use a scalpel and do surgery. Using the point of a new scalpel blade, I slice around the wart-like protrusion and then pluck it off the surface with fine-pointed tweezers. The result is a pot hole in the print.

© Douglas Mesney 2011
Photo-micrograph extreme close up shows 'pot hole' in glossy, laminated-canvas print surface.
Plucking off surface 'warts' leaves craters where the ground pulls away from the substrate.


Color & Fill Pot Holes

The substrate at the bottom of thee hole is paper (even if it is 'canvas'). The paper must be colored to match the surrounding tones... a process photographers call 'spotting'.

© Douglas Mesney 2011
Use watercolors to retouch the paper surface exposed at the bottom of the pit.
Give the color a texture to match the look of the areas around it, outside the crater.
Note that this crater's color looks too dark because it is not glossy
and doesn't reflect the light like the shiny laminate all around the hole.

Spotting
involves using a very fine tipped brush with water-color dyes to stipple flecks of color into the spot of white paper at the bottom of the hole. You'll be tempted to use a blob to do the job... don't. Build the tones up gradually, with the tiniest dots you can stipple, until they match those around them.

After spotting in the color, use a hair dryer to get the watercolor dyes thoroughly dry. Then fill the hole with a drop of the liquid laminate fluid (or varnish if you are repairing a previously varnished canvas).

Two, three or maybe even four drops will eventually be used to fill the hole. Let each drop cure entirely before adding another (at least one hour).

© Douglas Mesney c/o Michael Elenko 2011
Use a toothpick to accurately place a small drop of laminate fluid in the hole.

© Douglas Mesney 2011
The right amount of laminate will bulge out of the hole.
When it cures the drop will sink into the hole leaving a smaller crater.
Depending on the size of the crater, you will need to get back in there two or three times more to build up the 'caldera' in the crater until the surface looks like a well repaired pot hole in the road.

© Douglas Mesney 2011
Arrow points to light reflecting off rim of crater filled twice before.
Here a third, small droplet of laminate fluid has been placed in the slowly filling hole.


© Douglas Mesney c/o Michael Elenko 2011
Use a hair dryer to speed up curing and work the hardening laminate
in the hole with the tip of a toothpick to texturally match the surrounding surface.


Finish the repair with a new top coat of laminate across the entire surface. After that you may still be able to see the blemish. But unless you say nothing, nobody else will.

(Shhhhh!)




4 comments:

  1. This comment has been removed by the author.

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  2. I have a giclee with a dent. I have read instruction to dampen the back and allow to dry. Would this be the asked method for a giclee?

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  3. I have a giclee with a dent. I have read instruction to dampen the back and allow to dry. Would this be the asked method for a giclee?

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  4. I have giclee great had a dent. There are sites which suggest dampening three back and allowing to dry. Would I use the same method for my Dianne Parks giclee?

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