The general purpose of these designs are described in “3D Printed UV-vis Cuvette Adapter for Low Cost and Versatile Spectroscopic Experiments”, which is published in the open access journal ACS Omega. Link to publication:http://pubs.acs.org/doi/abs/10.1021/acsomega.7b01310

This particular part is meant to allow reproducible analysis of films on a microscope slide with a film. The light from the spectrometer is allowed to pass through a square shaped hole in the adapter to limit the region of the film analyzed. This adapter can be used in most standard UV-Vis spectrometers. We recommend printing this design with a black filament to reduce the amount of light scattering.