We examined a variety of colored components in order to choose a suitable quenching agent for producing quench curves. Figure 5 shows the UV/visible absorption spectra of a range of colored dyes, while Figure 6 shows the fluorescence emission spectra of yttrium silicate and PVT beads. All the dyes have absorption spectra that overlap somewhat with the emission spectra of the scintillant (from about 350-500nm), and so will cause quenching of the emitted light to a greater or lesser extent depending on the degree of overlap.