This very bright opaque yellow will stay true when drawn down to smaller cane sizes and will not transmit light unless the application of color is thinner than 2mm. This color works great in the neutral flame region and can handle all flame atmospheres for short amounts of time.  Do not use a highly reducing flame or a very sharp hot flame without quick movement of the color; this will avoid any possibility of minor boil spots. 

The vibrancy of Acid Yellow Crayon is a wonderful backing to many Glass Alchemy transparent colors, also a very complimentary color to the other opaques, and desirable for murrine applications as well.  Encasement in clear is not necessary but can be used to increase yield on size of solid or blown work and allow for more intense working conditions.