The subject of the present publication is the working practices of the Ghent-Bruges illuminators, active in Flanders in the decades around 1500. Its focus is on manuscripts featuring freestanding, isolated motifs painted in the margins of text pages. The author traces how this decorative system was created by the Master of the David Scenes in the Grimani Breviary, a prolific inventor of appealing borders, how it was applied by his closest collaborators, and how it was imitated and adapted by other illuminators. Among these were Simon Bening, the Carmelite sister Cornelia van Wulfschkercke, and a number of anonymous masters, including several whose oeuvres are identified here for the first time. The author elucidates the sources for the isolated motifs and demonstrates how the codicological structure of the manuscripts provides insight into the use and the dispersion of various models for border decorations. The book discusses the famous strewn-flower borders and other types of fully decorated borders as well. The author analyses the isolated motifs in relationship to the page layout and the decorative programme of Ghent-Bruges standardised books of hours. The stylistic examination of both the miniatures and the borders of the manuscripts under discussion completes the integrated approach of this study. The author demonstrates how the illuminators collaborated with each other and exchanged artistic models for the illumination of these precious manuscripts.