File Extension NPM File Format Neopaint Mask NPM stands for Neopaint Mask. This was last updated in March 2012 By Margaret Rouse Browse File Extensions Alphabetically: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Ask a Question. Find an Answer. Ask your peers a question about this file extension. Ask a Question Mask Table data Upgrading Node.js and NPM to latest versions How did your workstation obtain the IP address, Subnet mask and default gateway?