Albert Bierstadt (1830-1902) Cathedral Rocks, Yosemite Valley, California, 1872 Oil on paper Private Collection, Houston, Texas More about this work...

Jasper Francis Cropsey (1823-1900) Winter on the Hudson, 1887 Oil on canvas Collection of the Newington-Cropsey Foundation, Hastings-on-Hudson More about this work...

In America Cole, following European custom, executed small-scale oil studies in preparation for more elaborate compositions, and occasionally sketched in oil out of doors. From him, Church and Durand learned to do the same.

There was little or no formal training in the techniques of painting, and outdoor oil sketching established itself as an important if spontaneous discipline. In the 1850s it became a normal part of the landscape painter's practice, and artists like Sanford Robinson Gifford and John Frederick Kensett travelled to their summer sketching grounds up the Hudson or in the mountains of Vermont, New Hampshire and Maine armed with oil paints and easel as well as with sketchbooks, pencils and watercolours.

Church made especially prolific use of the medium, taking his implements to South America, Jamaica or the Arctic, and continued to do so until late in his life, producing some of the most beautiful of all landscape studies in oil. Many of these record the spectacular scenery round his home, 'Olana', perched above the Hudson opposite the Catskills. Bierstadt's approach to the oil sketch was influenced by his time as a student in Düsseldorf, where the academic value of a rigorous technique was central to the training. His oil studies range from sketches of animals - bear, buffalo, cattle - to mountain peaks, trees, American Indian encampments and surveying parties on the trail. He also produced more elaborate subjects on a relatively small scale, which although fresh and directly observed 'are not sketches, nor are they studies - they are pictures'.