A LIP file is an image file created by Clip Studio Paint, an application used to draw manga (Japanese-style comic books and graphic novels), illustrations, and animations. It contains a composition which consists of one or more layers (raster or vector) and may include pencil, pen, or brush strokes, shapes, text, and images.

LIP files are similar to .PSD files used by Adobe Photoshop as they are used as a project file which allows you to resume your work at a later time. The LIP file also supports RGB, CMYK, and HSV color, layer masks, filters, and other effects. The LIP file was replaced by the .CLIP file when Clip Studio Paint moved from the Clip Studio Paint format to the Clip Studio format in version 1.5.4. The newer format in CLIP files allows for quicker load and save times as it is a lighter format than the old Clip Studio Paint format in LIP files. You can still save your images as LIP files in Clip Studio Paint version 1.5.4 or later, however, the LIP file will no longer be able to be opened in versions 1.4.4 and earlier after it is edited in versions 1.5.4 and later.

File used by Real Virtuality, a Bohemia Interactive game engine used for games such as Operation Flashpoint, the Armed Assault (ArmA) series, and Virtual Battlespace series (VBS1 and VBS2); contains lip sync information used for NPCs (non-player characters).

LIP files are synchronized with a .OGG audio file that is converted from a mono, 16-bit .WAV file using Bohemia Interactive's WaveToLip (or "Wav2Lip") program. LIP files must have the same filename prefix as the OGG file. For example, sound1.ogg and sound1.lip are compatible filenames. NOTE: When creating LIP files with WaveToLip, the corresponding WAV file must not have whitespace characters in the file path, and the path must be short in length.