https://www.internationalcrystal.net/wp-content/uploads/ICL-Disposable-Sample-Cards-Quality.pdfICL has brought back the 3M® card, which we manufacture under a license from Minnesota Mining and Manufacturing Company. PTFE and polyethylene IR sample cards provide inexpensive disposable sample substrates for qualitative analysis. The 2" x 4" cards mount vertically in the universal slide mount in any spectrophotometer. The cards have two clear apertures of 19mm and space is provided to write on the card to identify the date of the analysis, the sample and the name of the analyst.