Answer to What is This on the Cover of American Laboratory October

The image on the cover of American Laboratory October depicts a late 18th-century plaster sample from Philipse Manor Hall, New York State Historic Site. The sample is a lime-based plaster with animal hair reenforcement. The image was captured by Mary Betlejeski and Erin Moroney (Division for Historic Preservation, New York State Office of Parks, Recreation and Historic Preservation, Waterford, NY) utilizing quantum dots excited by ultraviolet light (350 nm). Quantum dots fluoresce an intense pink color indicating the presence of the consolidant. Quantum dot-tagged consolidant was applied by pipet to the sample: Quantum dot (Evident Technologies T2 Evi Dot™ Maple Red Orange [CdSe]); Consolidant (Paraloid B72 [methyl acrylate and ethel methacrylate]). Total original magnification was 300×.

Congratulations to Gary Tapp, this months winner of the $10 Amazon gift card.