Iv been hearing a few people saying that the notion that gloss varnish protects better than matt isn't actually true and that the quality of protection they provide is equal.
Is this true or is it nonsense?
pfft. you are all crazy - you can taste the difference when you lick your brush. matte tastes waaaaaaaaaaay better :brushwave:
Very droll.
PSA: Acrylic paints and mediums contain formaldehyde, ammonia, and chemicals such as surfactants and anti-foaming agents, and that’s not even getting into the complex organic compounds that are modern pigments.
Do not let acrylic paint, varnishes, or mediums near your mouth.
[h=3]VARNISH TROUBLE-SHOOTING[/h] If milkiness or opacity occurs in varnish layer, then
If reflectance is not uniform, then
- if using a satin or matte varnish, and this only occurs over dark colors, this may simply be the nature of such a reduced sheen varnish (caused by the presence of the matting agent). There is no way of applying a satin/matte finish to a dark color without lightening it (the more matte the finish, the more potential for lightening dark areas). To restore the depth of the dark colors, apply a higher gloss to restore some of the sheen.
- if this is uniform across much of area, regardless of the darkness of the underlying colors, it may be caused by moisture entrapment. High humidity or a damp surface under the varnish layer often causes loss of clarity. Using a warm, forced air source to blow across the surface should help the moisture evaporate, restoring clarity.
- if varnish is not properly thinned, or is shaken or stirred excessively, air bubbles may become trapped within the dry film, causing a loss of clarity. The varnish must be removed.
- if a "frosted" area appears, a satin or matte varnish may have been applied over an absorbent surface (this is common for spray applications). The varnish must be removed, the surface sealed to reduce absorbency (apply gloss varnish), followed by application of a reduced sheen varnish.
If brush strokes remain, then
- if surface has varying absorbency, this may result in uneven gloss. Ideally, such a surface would first have isolation coat applied to provide a more uniform surface. However if varnish has already been applied, the surface must be sealed by applying 1 or more additional coats of gloss varnish, followed by the desired sheen varnish.
- improper mix of varnish. The varnish/solvent mixture was not thoroughly mixed. If different sheens were blended together (gloss with matte), they may not have been thoroughly mixed. If the diluted varnish is used over a long period of time without restirring, it may be separating (matting agents settling). To achieve a uniform finish, start with a fresh mixture of varnish/solvent (thoroughly stirred) and apply another coat (may also consider removing the existing varnish layers).
When spraying, if the surface is very pebbly or textured, then
- the varnish may not have been thinned sufficiently to level during application.
- the solvent was not compatible with the varnish.
- if the surface was absorbent, it may have caused the varnish to dry too quickly, and not allow it to level.
If the varnish is sinking in and not developing sufficient gloss, then
- the varnish may have dried before reaching the surface. This could be caused by insufficient thinning (add more solvent), an extremely dry environment (add humidity, reduce heat, limit air flow) or by excessive air flow (reduce air pressure).
If the varnished surface is too glossy, then
- the surface is too absorbent. Apply additional coats of isolating layers (only if no varnish is yet applied) or gloss varnish. Excessive dilution of varnish may also result in this problem.
If the varnished surface is too matte, then
- apply a satin or matte finish of the same kind of varnish already applied.
- apply a gloss or satin finish of the same kind of varnish already applied.