For a glitter to work in nail polish, it needs to be solvent resistant (sometimes refered to as solvent stable). A non solvent resistant glitter can bleed and/or melt when added to a lacquer base.
Bleeding refers to a solvent resistant glitter with a non-solvent resistant color coating, i.e. a color that is soluble in the solvents that make up lacquer bases. As opposed to a melting glitter, a bleeder will maintain its shape but lose some or all of its coloration to the base. The process might be quick (minutes) or slow (weeks or even months). Whether bleeding occurs or not is not only dependent on the glitter, but to a smaller degree also on the type of suspension base used. Because of this, it is often adviced to try all glitters in suspension base and shelf them for 6 months before using them in a larger batch.
Many glitters sold as "craft glitter" will bleed in lacquer base.
Glitter size is often measured in inches or fractional inches, or more uncommonly in millimeters. Microns (also known as micrometers) are more commonly used for pigments. 1 millimeter equals 1000 microns.
The most commonly manufactured shapes of glitters are:
- Hex - hexagonals. Note that when the size is small enough hexes might appear as spherical shapes.
- Bars - sometimes termed slices. Rectangles that commonly have a 1:10 length ratio between sides. 1:5 length ratio bars are sometimes termed short slices or rectangles'.
- Dots - circle shaped glitter that often are 0.040" or larger.
- Shreds - randomly cut
Other shapes such as hearts, stars or flowers exists. These come only in larger sizes, around 0.125".