A partwork is a written publication released as a series of planned magazine-like issues over a period of time. Issues are typically released on a weekly, fortnightly or monthly basis, and often a completed set is designed to form a reference work on a particular topic.
Partwork series run for a determined length and have a finite life. Generally, partworks cover specific areas of interest, such as sports, hobbies, or children's interest and stories such as PC Ace and the successful The Ancestral Trail series by Marshall Cavendish Ltd. They are generally sold at newsagents and are mostly supported by massive television advertising campaigns for the launch. In the United Kingdom, partworks are usually launched by heavy television advertising each January.
Partworks often include cover-mounted items with each issue that build into a complete set over time. For example, a partwork about art might include a small number of paints or pencils that build into a complete art-set; a partwork about dinosaurs might include a few replica bones that build a complete model skeleton at the end of the series; a partwork about films may include a DVD with each issue. In Europe, partworks with collectable models are extremely popular; there are a number of different publications that come with character figurines or diecast model vehicles, for example: The James Bond Car Collection.
In addition, completed partworks have sometimes been used to create case-bound reference works and encyclopedias. An example is the multi-volume Illustrated Science and Invention Encyclopedia which was created with material first published in the How It Works partwork.
In the UK, partworks are the fourth-best selling magazine sector, after TV listing guides, women's weeklies and women's monthlies. A common inducement is a heavy discount for the first one or two issues. The same series can be sold worldwide in different languages and even in different variations.