Top row: the ratio of icy-to-total C¹⁸O abundance of the best-fit models is plotted against the core radius, the hydrogen number density, the column density, and the dust temperature. Bottom row: the N₂H⁺ abundance (relative to the hydrogen density) is plotted against the same quantities. The dashed lines indicate the results of the individual globules. Where the models cannot be compared to observations (because the line radiation is too weak), the dashed lines turn into dotted lines. The bold solid lines mark the mean values. The gray area indicates one standard deviation.