Scintillation crystals can be tailored by modifying their chemical composition to enhance performance for specific applications. For instance, introducing a small amount of a dopant can boost the crystal's light output, as seen with thallium-doped sodium iodide (NaI(Tl)) and cesium iodide (CsI(Tl)). Additionally, certain dopants can influence the decay time of the scintillation process, such as yttrium-doped barium fluoride (BaF₂-Y). Co-doping with multiple elements allows for further adjustments to the energy response and improvements in scintillation efficiency, exemplified by calcium-co-doped LYSO(Ce) (LYSO(Ca, Ce)).

Surface treatments include cutting, lapping, polishing, and coating can be applied to crystals to reduce light scattering, enhance light collection efficiency, and achieve good uniformity and energy resolution. For example, a customized scintillation crystal may be ground to a specific particle size (in micrometers) using different grades of sandpaper, such as W14 and W28. Additionally, mechanical polishing used T0285 may be performed to increase the number of photons reaching the light sensors.

Reflector materials, including BaSO4, TiO₂, E60, ESR, and Teflon etc. can significantly improve light collection efficiency when applied to individual scintillation crystals. These reflectors can also be used in pixelated crystals to reduce crosstalk between neighboring pixels. For instance, BaSO₄ and ESR are commonly used with LYSO(Ce) and BGO in PET/SPECT applications, while TiO₂ is employed in CsI(Tl), CdWO₄, and GOS for industrial CT and X-ray security inspections.

The scintillation crystals can be tailored with specialized encapsulation to enhance their performance and safeguard them against environmental factors like humidity, temperature, shock, and vibration. For instance, hygroscopic materials such as NaI(Tl), LaBr₃(Ce), and CeBr₃ all require aluminum housings and optical windows to protect against moisture.