Fig. 4From: Water-stable, biocompatible, and highly luminescent perovskite nanocrystals-embedded fiber-based paper for anti-counterfeiting applicationsAnti-counterfeiting application. Alphabet “NPL” and QR code patterns printed with blue, brown, green, and yellow on an inkjet printer using a reverse printing approach on fluorescent PCL-perovskite fibers-based white paperBack to article page