If anyone out there is considering building an IR-related project and is looking for something to block visible light but pass IR, consider the wrappers from M&S Cherry Liqueur Chocolates !
Each wrapper is about 10cm square. Eight layers were found to be enough to drastically attenuate visible light while having no noticeable effect on the IR from a TV remote. The only side-effect of creating a filter this way is a slight increase in the dimensions of your waistline.
Each wrapper is about 10cm square. Eight layers were found to be enough to drastically attenuate visible light while having no noticeable effect on the IR from a TV remote. The only side-effect of creating a filter this way is a slight increase in the dimensions of your waistline.