One of the most common indicators of use over the years is the marks that are present in the Ryerson & Burnham Libraries' collection of manuals. Readers over centuries have left sketches, annotations, and insertions of related materials that show that they kept these volumes close at hand.

Some of these books were designed for readers to sketch in, such as Vere Foster's Drawing Copy Book, which provided figures for students to draw to acquire “hand power and artistic quickness.” In other cases, artists probably sketched in the books because they were nearby; this appears to be the case with the sketch of his brother that Sir Edwin Landseer inscribed in his copy of A Practical Treatise on Painting in Oil Colors.

Sometimes readers marked books in order to note an area of the text they found particularly engaging so that they could return to it easily. This is the case with one of the Libraries' copies of Vitruvius's treatise on architecture, De Architectura (On Architecture). An early reader has annotated the section on water in Book 8 of this copy of the book, which was published in Venice in 1511.

A reader's notes are also present in the Libraries' copy of Livre de Perspective (Book of Perspective), published in 1560. This book was acquired from the library of the French architect Pierre François Léonard Fontaine (1762-1853), who may be the reader who recorded these notes about Cousins's description of foreshortening.

In addition to annotating the text of A Brief Account of the Composition and Permanence of Artists' Colours (“Very useful,”) a reader (possibly Beatrice Tolman Sawyer, who inscribed the front cover) used the book to store a manuscript copy of a recipe for a pastel fixative, suggesting the book was kept nearby while the reader was working. It is remarkable that the inserted note stayed united with the book through the present day.

1. Foster, Vere. Vere Foster's Drawing Copy Book. Q1, Human Figure. London: Blackie & Son, ca. 1870-1900.
2. Sketch by Sir Edwin Landseer in Practical Treatise on Painting in Oil Colours. London: Printed for E. and J. White, 1795.
3. Practical Treatise on Painting in Oil Colours. London: Printed for E. and J. White, 1795.
4. Vitruvius Pollio. M. Vitrvvivs per Iocvndvm solito castigatior factvs cvm figvris et tabvla vt iam legi et intelligi possit. Impressum Venetiis: Ioannis de Tridino alias Tacuino, 1511.
5. Cousin, Jean. Livre de perspectiue de Iehan Cousin, senonois, maistre painctre à Paris. A Paris: De l'imprimerie de Iehan le Royer Imprimeur du RoyÉs Mathematiques, 1560.
6. Winsor & Newton. A Brief Account of the Composition and Permanence of Artists' Colours as Sold by Winsor & Newton, Ltd. London: Winsor & Newton, 1895.