which is best to use boiled or raw linseed oil for oil paints glazes?

Answer 1

The best linseed oil which is archival quality is Refined Linseed Oil. It is made from falx and is better than cold pressed , boiled or other linseed oil because it doesn't yellow as much as other linseed oil. I like Gamblin because it is a lot less acidic than other brands.

Answer 2

For glazes you need as fine an oil as you can get. Plain raw or boiled does not cover it.

Use raw bleached for best effect. The boiled version often has other oils added and can color rather yellow when dry.