Protective Sealer for Paper Collage Paintings

"Sealing Coats"

"The function of a sealing coat is to reduce the absorbency of the substrate and also to encapsulate the inks, making them less susceptible to reacting with subsequently applied materials. It also seals the substrate’s ink-receptive coating if one is present. Each substrate will have a unique degree of absorbency and reaction to the initial sealing coats applied to it. Sealing allows for uniform varnish coats and the ability to apply and manipulate subsequent products more readily. Once a uniform layer has been established, the artist is free to “re-mark” — the post manipulation of a print with color and texture — with paints, gel mediums, or varnishes.

In many cases it can be difficult to apply water-based coatings directly onto the print without some color bleed — even systems deemed “water resistant.” Spraying provides the most even application of these coatings. Light, fast-drying seal coats can minimize the occurrence of inks bleeding or distortion of the image.

Once it is established that a waterborne coating can be used, then determine what properties are desired with this coating and what application method works best. For example, GAC 500 blended with Airbrush Transparent Extender makes a good overall spray coating, while Soft Gel (Gloss) thinned with water is better for brushing. Thin coats are best to seal the surface. Absorbent papers may require several coats to properly seal the paper. Gloss products provide better clarity and depth of color than semi-gloss or matte products.

If the image is too easily blurred with a direct application of a water-based coating, the most practical solution is to apply the GOLDEN MSA Varnish (Gloss) or Aerosol Archival Varnish (Gloss) as the primary sealing coat. This solvent-based acrylic varnish should not react with water-soluble inks or ink-receptive coats."

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