This study focuses on three series of manuscript fragments dating from the seventh to the tenth century where passages of the Psalter were copied. Most of the fragments are currently preserved at the Library Abbey of Sankt Gallen, and their digital reproductions are available on Fragmentarium: Cod. Sang. 1395 II, pp. 336-361 [F-4b1o]; Cod. Sang. 1395 III, pp. 368-391 [F-jo7w]; and Cod. Sang. 1397 V, pp. 1-12, 37-42 [F-i8qo]. These fragments provide the basis for identification of the primary characteristics of their original codices as well as information on the texts they transmit: their content, the version of the Psalter used, marginal notes, and the use of the manuscripts after they were copied. Likewise, the subsequent reuse of these manuscripts, once transformed into fragmentary material, is reconstructed, specifically concerning their dispersal in several libraries, being bound in host volumes, evidence from offsets, and traces of missing fragments. This study leads to some basic methodological conclusions on how to deal with collections of fragments, emphasizing the vast and fruitful research opportunity presented by such collections, especially the collection of manuscript fragments at the Library Abbey of Sankt Gallen.