PortalGun-4.0.0-beta-4.jar is a release file of the Minecraft resource pack Better Paint, made for Minecraft 1.7.10. It was published on April 13, 2015 and is 0.6 MB in size. For the full description, screenshots and every other version, visit the Better Paint resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.
