Substrate pre-treatment - what options are there?

Impregnations, primers and special primers as well as masking agents

 

Impregnations and primers are used to optimise the preparation of a painting surface and are therefore the basis for the longevity of a work of art. Impregnations are usually transparent and colourless. They are used before the actual priming to pre-glue highly absorbent surfaces, such as raw linen, wood or cardboard, but also to strengthen mineral, usually slightly sandy surfaces such as plaster or concrete. For non-absorbent substrates, such as plastic or metal, we recommend AERO GRUND (50601) as the first coat before applying the primer of choice.

Primers are available in both transparent and opaque, white or natural colours, fine or coarse, more or less absorbent. They are used to change and standardise the absorbency of the individual painting surface, give it a certain structure and optimise the adhesion of the subsequent paint.

TIP: If a different colour shade of impregnation or primer is desired, the products can be individually coloured with Schmincke acrylic paints. With the exception of the speciality oil primer/underpainting white (50517), all the products described below can be thinned with water, but dry relatively quickly and are insoluble in turpentine oil. Tools such as brushes, painting spatulas or paint rollers should therefore be cleaned quickly after use with soap and water. In ‘emergencies’ we recommend special cleaning with ÖKO-Pinselreiniger (50052) on a water/alcohol basis. As a rule, the impregnation - if necessary - should be applied in two thin coats before applying two to three thin coats of the respective primer. The first layer of impregnation or primer is best diluted with a little water. It is important that the previous layer is always completely dry before the next one is applied.
completely dry before applying another coat. In general, you should carry out individual pre-tests with all painting materials to be used!

TIP: There is a simple ‘TESA® tape test’ for testing the adhesion of a paint layer to a specific substrate: To do this, the adhesive tape is rubbed onto the dried surface - impregnation, primer and/or paint layer - and pulled off again with a jerk. If nothing sticks to the adhesive tape, adhesion is good. Impregnations and primers should not be applied below an object temperature of 10 °C. The following also applies to their storage: Protect from frost

Masking agents are used for temporary partial masking of areas of the picture that are not to be processed on relatively smooth, grease-free and dry surfaces, such as paper, smooth drawing board, photos and films. Schmincke offers them either colourless or - for better contrast on white surfaces - coloured blue. The user can also choose between various applications. The masking pen allows details to be masked directly thanks to its practical packaging: a plastic bottle with a fine tip. Scratch crepe in a jar can be applied with a cotton bud, a wooden stick, a quill or a drawing pen. Schmincke's masking fluids contain a synthetic, ammonia-free binder and are therefore odourless - in contrast to the natural latex emulsions often used for this purpose. They are ready to use and dry quite quickly to form a rubbery, transparent or bluish film that is insoluble in water. All tools should therefore be cleaned immediately with soapy water. We also strongly advise you not to use valuable brushes. Incidentally, the dosing tip of the masking pen is best cleaned with a needle when it is dry.

TIP: If the tip of the masking pen is still too ‘coarse’ for you, it is of course possible to make the opening smaller with the help of a fine metal nozzle. You can usually find these in well-stocked specialist shops with the contour bottles for e.g. porcelain paints or window paints. Once the masking fluid has dried completely - which can take a few minutes or more than an hour, depending on the thickness of the layer - the covered areas of the picture can be painted over with water-based paints such as watercolours or AERO COLOR® Professional. Once this layer of paint has also dried well, the rubbery film of masking fluid can be removed by carefully rubbing it off with a dry, grease-free finger (please do not peel it off!).
ATTENTION: The masking film should not remain on the substrate for longer than 2 days and must be completely removed.
must be removed completely; there is a risk of yellowing of the substrate! Incidentally, particularly soft, weakly sized papers with structure, such as rag or torchon papers, are not suitable for the masking technique. It is therefore important that you subject your substrate of choice to an individual pre-test! The following also applies to all masking agents: Shake the container before use and close tightly as soon as possible after use. Protect from frost.