This screenprint with additional pochoir (both stencil processes), is a proof. It is unsigned, but is initialed in the lower right corner, sideways.
Cramer emigrated to the US at age 23 from Germany and was aware of the European Modernist movements, including Cubism. His interest in Cubism can be found in this still life, a flattened post Cubist composition done using stencils. Screenprinting, a stencil process had come to the fore during the Great Depression and the PWA/WPA, where it evolved as an art form.
The pochoir process also uses stencils but without silk and the ink is applied directly to the image, without any silk texturing to the ink.
Cramer went on to involve himself in modernist photography after meeting Alfred Stieglitz, experimenting with solarization and multiple exposures.