Grounds and primers are used to prepare the support in optimum manner and ensure the long life of the work of art. Grounds are normally transparent and colourless. They are used before actual priming to prepare highly absorbent supports like, for example, linen canvas, wood or board, but also to firm up slightly sandy mineral-type surfaces like plaster or concrete. For non-absorbent supports like, for example, plastic or metal, we recommend using AERO GRUND (50601) as first coat before applying the primer of choice. Primers may be formulated to be transparent or opaque, in white or natural colours, fine or coarse, highly or weakly absorbent. They are used to modify and even out the absorbency of the individual support, give it a certain texture and optimise the adhesion of the paint subsequently applied.
HINT: If a ground or primer is required in a different colour shade, the products can be individually coloured using Schmincke acrylic colours. Except for the special product oil primer/white undercoat (50517) all products described below are water-thinnable and dry relatively quickly to become insoluble in water or oil of turpentine. For this reason, tools like paint brushes, paint scrapers or paint rollers should be cleaned with soap and water promptly after use. In an “emergency”, we recommend using a special cleaner such as Eco brush cleaner (50052) with a water-alcohol base. If ground is required, it should normally be applied in two thin coats before applying two or three thin coats of the relevant primer. It is best to thin the first coat of ground or primer with a little water. It is important for the previous coat to be completely dry before the next coat is applied. As a general rule, you should do a test beforehand with all the painting materials that you intend to use!
HINT: To check the adhesion of a coat of paint to a certain support, you can do a simple Sellotape® test: Rub the Sellotape® onto the dried surface – ground, primer and/or coat of paint – and then tug it off. If nothing adheres to the adhesive tape, then adhesion is good. Grounds and primers should not be applied to objects with a temperature below 10 °C. They must also be protected against frost during storage!