Can lacquered?
 

I would like to know. As with any paint to cover the picture that-be as little as possible was glare? And whether lacquered picture painted with tempera or gouache.

Mat and spray.
Best option, do not glare.
There are in sales, good-English, Italian.

Ahead. 1

gans, confirmed.

This applies to gouache?

No, to the oil.
Gouache paint is not covered.
Some use a fixative for pastels, charcoal, watercolors, tempera.
Fissativo per carboncino, matita, pastello, acquerello, tempera.
Or Perfix colourless fixative.

Gouache in any case not covered by anything, it will be defaced, altered color spots. Tempera possible, but carefully. The fact that the tempera paint on varnish (dammarnogo) will be brighter, artists and earlier, and now it is included. If painting on paper, do not risk - it can be mixed technology, ie and wc. and gouache and tempera, spoil. If it is on the canvas, it is also no assurance that oil paints are not present in some parts, temperatures often serves podmalevka. When the varnish is using the artist himself, he knows where that. In this case, he does so: a thin layer of gelatin covers only part of distemper, two days together with varnish. In any case, the picture changed slightly to become a little brighter, but slightly darker.

This is not to expensive paintings. In other cases only the individual approach.
More less similar technology described on the site-http://paintingart.ru/articles.php?zag1=5&zag2=0
And it must be borne in mind, the brush should be in the hands of a master.