The catalogue of glass objects presents materials from the remains of former forest glassworks in the area of Trebuša and Trnovski gozd (Mrzla and Mojska draga), which historical sources also refer to as the Gorizia glassworks (1722–c. 1830). The catalogue offers insight into production processes, product circulation, and glassmaking in forest glassworks. Most objects produced in the Trnovski gozd area, now held in museums in Gorizia, Ljubljana, and Tolmin, originate from former glassworks or private collections and are the result of field research conducted before the First World War by the brothers Giovanni and Ranieri Mario Cossar, Gorizia historians, ethnographers, and later directors of museums in Gorizia.

The catalogue includes both everyday and technologically advanced glass, while fragments and slag allow for more reliable interpretation and determination of origin. The finds contribute to understanding the development of glassmaking in Central Europe from the early modern period to the 19th century and demonstrate the inclusion of the Gorizia outskirts in the cultural and intellectual trends of the time.