PROTECTING INKJET AND OTHER COMPUTER PRINTS FROM UV
The inks used in computer printers are made from dyes, which are typically fugitive. Computer-generated prints need to be protected from the damaging Ultra-Violet (UV) rays from the sun and other light sources.
APPLICATION DESCRIPTION
Protecting Computer Prints
Most computer printers use ink systems that contain water-soluble dyes. Dyes are typically fugitive, which means that they readily fade when exposed to sunlight or any light source containing UV wavelengths.
Aside from the need for UV protection, the print also needs to be protected against water, moisture and handling to keep the image from smudging.
PROTECTIVE PRODUCTS
Glass and Acrylic Sheets
Normal glass and "Plexiglas" acrylic sheets do not offer UV protection. Sheets that do offer protection are expensive and usually impractical for the average artist. This type of protection also limits the manner in which a print can be safely displayed.
Fixatives
Although there are several solvent and alcohol-based "fixatives" on the market, they typically do not offer UV protection, although some do offer water-resistance.
UV Protective Coatings
There are other systems that claim to offer UV resistance to fading. However, all those tested by Golden Artist Color"s Laboratory failed to offer the protection of the MSA Varnish. Most offer only marginal protection, while GOLDEN MSA Varnish provides significant improvements in lightfastness1.
GOLDEN MSA Varnish
GOLDEN MSA Varnish is a mineral spirit-based acrylic varnish that gives computer prints water-resistance and UV protection. Although Golden Artist Colors does manufacture a water-based Polymer Varnish, it should not be used for computer prints. Because the inks are water-soluble, any water-based product will smear, blur or otherwise distort the image on the print.
Future Product Developments
The Golden Artist Colors laboratory is pursuing an aerosol-propelled system for the MSA Varnish. Currently, MSA Varnish is only available in a viscous form that requires dilution for brush application and can also be reduced further for spraying.
A custom version with higher level of UV inhibitors and absorbers is currently being developed, specifically for the purpose of coating fugitive ink prints (inquire if interested). This custom formulation will decrease the number of coats required (depending on the absorption of the paper or material printed).
PRINTER & INK SYSTEMS
This field is rapidly growing and manufacturers are constantly making improvements in the quality of their inks and printers. While we have tested a wide variety of ink systems from various manufacturers, we believe that you should rely on your own testing and information gathering to make the best decision as to which systems to use.
APPLICATION PROCEDURES
Maximum Protection Procedures
Allow 4 to 6 hours between coats for sufficient drying. Significant level of protection is achieved with 4 to 8 coats of MSA Varnish (4 coats brushed; 8 coats sprayed). A minimum of 2 brush-applied coats is recommended for highly absorbent surfaces such as paper. Ideal protection is reached with 3-4 brush coats of the MSA Varnish. Generally, if a matte finish is desired, brush on 2 coats of MSA Varnish Gloss, followed by a coat of MSA Varnish Matte. If spray equipment is available, the final brushed-on layer of Matte Varnish can be replaced with 2 sprayed coats of the same. If all layers are to be sprayed, it is advisable to spray on 6-10 coats to provide substantial protection. It is advisable to brush on the first layers of Gloss Varnish, as this maximizes the amount of UV stabilizers that penetrate into the absorbent surface.
Sheen Considerations
The first layer(s) of MSA Varnish applied to a print should always be gloss. This is because of the absorbency of paper. If a Satin or Matte Varnish is applied first, the varnish itself will be readily absorbed into the paper, leaving behind the matting agents. This will cause a "frosted" appearance on the surface, especially apparent over darker ink passages.
Gloss Sheen
Apply desired number of coats of MSA Gloss Varnish only.
Satin or Matte sheen: apply MSA Gloss for the first several coats (2 for brushing or 4 for spraying), followed by desired lower sheen MSA Varnish. This will eliminate the "frosted" appearance mentioned above, and have better clarity than several coats of a matted product.
Proper Thinning of the MSA Varnish
MSA Varnish must be thinned as specified on the label directions. Thin with mineral spirits or distilled turpentine (always use fresh supply of turpentine). For brush-application, thin 10-30% (a 3:1 varnish/thinner ratio is a good starting point). For spray-application, thin 1:1 with solvent (larger spray equipment may be able to spray a 2:1 varnish/thinner mixture). It is important to test the thinned varnish for proper application properties before proceeding on a finished piece.
(Note: For more complete information on MSA Varnish, application procedures and other information, refer to the Varnish Application Information Sheet, the MSA Varnish Information Sheet and the Acrchival Spray Varnish Sheet).
UV PROTECTION
We have done a series of tests, conducted in Golden Artist Colors laboratory, using a QUV Weatherometer equipped with UVA-351 bulbs to determine the relative performances of various inks and protective varnishes. Exposures of 1200 hours under these conditions have been correlated to be equivalent to 100 years of museum light conditions. Exterior exposures will be much more demanding, leading to earlier degradations and significantly faster fading.
Generally, the results have shown that the inks with no protection have performed quite poorly, showing losses of 60-95% in color intensity. Prints protected with the 4 brushed on coats of the standard MSA Varnish show minimal to 20% loss of color intensity. There is a direct correlation between the amount of MSA Varnish and the degree of protection provided. When 2 brushed coats or less are applied, the results show moderate protection, but at an insufficient level to be considered archival2.
WATERPROOFING
The recommended applications of MSA Varnish result in dramatically improved resistance to water and moisture. While the varnish will not make them completely water insoluble, the varnished prints can withstand normal handling without the fear of smudging of images.
DEFINITIONS
1Lightfast - the ability to withstand color change due to exposure to light
2Archival - the ability to last a long time
Disclaimer
The above information is based on research and testing done by Golden Artist Colors, Inc., and is provided as a basis for understanding the potential uses of the products mentioned. Due to the numerous variables in methods, materials and conditions of producing art, Golden Artist Colors, Inc. cannot be sure the product will be right for you. Therefore, we urge product users to test each application to ensure all individual project requirements are met. While we believe the above information is accurate, WE MAKE NO EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, and we shall in no event be liable for any damages (indirect, consequential, or otherwise) that may occur as a result of a product application.
