A technique has previously been described for secondary school-aged children to make ultraviolet (UV) dosimeters from highlighter pen ink drawn onto strips of paper. This technique required digital comparison of exposed ink paper strips with unexposed ink paper strips to determine a simple calibration function relating the degree of ink fading to measured levels of UV exposure. In this article, the ink calibration process is discussed in relation to activities that can be performed by primary school-aged children. Further extension of the technique is discussed in relation to UV absorption by various transparent materials, and a simple exercise is explained that could be used by primary and secondary students to measure and calibrate UV exposures using a glass plate dosimeter. (Contains 1 table and 6 figures.)