The enamels are colors that have been traditionally used for ages in painting on glass at lower temperatures. They fire mostly translucent unless otherwise stated in the name.
What’s the difference between all the white enamels?
The D2070, D2617, and D20129 are all translucent and matt. The D2070 is the most translucent, then the D2617 has a little more pigment, and the D20129 has the most. All three fire quite matt.
The DX603 and DX660 are opaque and semi-matt. The DX660 has great pigment load and does not yellow at all.
The D20511 is opaque and quite glossy, and a touch warm.
The D2879 is a low-fire flux used in the transparent series. Used by itself it is a clear enamel. It can be added to colors to make them more translucent, or added to higher temperature colors to bring the firing temperature down.