Dvd case

A keep case or poly-box is a type of DVD (and sometimes Compact Disc|CD) packaging. these types of dvd storage cases is made of soft plastic material and with a cpp sleeve outside of the box to holder the paper insertions.

Physical dimensions
The height and width of a keep case is fixed. The thickness of the case may vary to accommodate more discs (multi case) or to require less shelf space (slim case). The typical single disc case measures 190mm × 135mm × 14mm (7.48in x 5.3in x .55in); the height is very close to the 188mm standard width of a VHS Videocassette recorder|videocassette, allowing DVDs to use shelving intended for VHS media.

Similar, though not identical, packaging is used for commercial HD DVD and Blu-ray Disc titles. However, the dimensions of the cases are somewhat different, about 19 mm shorter. The individual cases are color-coded, with blue being used for Blu-ray and red for HD DVD, and the format displayed prominently on a stripe above the cover art.

Materials and features
The cases are made of soft, usually dark gray, black or white (although a variety of other colors are produced) polypropylene plastic with a transparent polyethylene outer jacket, usually with a printed paper sleeve behind it. Keep cases are available in a variety of colors, including a lime green version exclusive for Xbox games. On the inside are sets of clips that may hold a booklet or additional sheets of paper with extra information. The DVD is held into place with a small protrusion (a "hub") which fits into the hole in the DVD. For console games like the PlayStation 2 and Nintendo GameCube, an extra protrusion is available for storing memory cards.

Paper sleeve and inserts
The printed paper sleeve for a standard DVD case can be printed on a standard A4 sheet of paper and slipped into the outer jacket. The front and back panels are 129.5mm × 183mm with a 14mm/9mm/7mm × 183mm spine panel. Booklet inserts or leaflet material, when folded closed, should measure to a maximum of 120mm × 180mm.

Usage
According to the Internet Movie Database, as of October 30 2006, there are 18,313 DVDs with sufficient information in the database that are packaged in a keep case.

In the days before video games were released on optical media, cartridges would sometimes come packaged in specially designed plastic keep cases with lugs inside to hold the instruction manual, as opposed to pressboard boxes (which buyers seldom kept along with the game, and are therefore very collectible today). Cartridges for the Sega Master System platform were the first video games to be packaged in any kind of keep case, and they were used in 100% of its game library. The vast majority of Sega Genesis games would come in a plastic keep case, but were later packaged in pressboard boxes, as a cost-cutting measure.

Before the standard, commonly used DVD case was invented, early CD-ROM based video games (such as Sega CD and early PlayStation titles) would often come in a taller keep case, which resembled a thicker and taller jewel case. These have been reputed to break very easily.

Today, all major console-based video game software is packaged in some sort of keep case, including Nintendo DS cartridge titles, and Sony PSP titles.