Some refer to this finish as soft crackle....... Being heated more than usual to soften the edges more than commonly seen. Another style of glass referred to as crackle by some appears to contain small fissures in the glass itself. An example of this style of crackle is shown in the last image, a vase by Welz.
Crackle glass is not necessarily a single color of glass, although that is the most common type that people are familiar with. Kralik did several crackle glasses in two colors, with a colored ground and a white cracked casing being one of the more unusual. Several examples of two color Kralik are attached.
Loetz Mimosa (the decor name for what was originally referred to as crackle) is generally a gold irridized glass over a clear ground, although there are examples known on colors also.
Many people, especially Americans, use the term "Stretch" to describe an onion skin effect.... American stretch is an onion skin effect exclusively, which is obtained by applying metallic salts to the surface of a formed piece and reheating it to create the onionskin effect caused when the glass expands more than the metallic salt surface.
examples here:
Shetlar Stretch GlassCraig