Writing a Book or Book Chapter
Publishers usually require evidence that you have obtained copyright clearance for third party content included in your book or book chapter. Third party content includes any material from other sources such as diagrams, charts, maps and so on.
Your book or book chapter might also include unpublished works such as extracts from private letters, postcards, diaries as well as photographs. Be careful when dealing with unpublished works because you will always need the permission of the copyright owner before publishing this material. Under UK law, this is true even when the work in question is very old: an unpublished manuscript by Jane Austen or Lord Byron would be protected by copyright until the end of 2039. When the author has died, in many cases copyright belongs to the individual's estate rather than to an independent archive now housing any collection, unless the archive has entered into a formal contract under which the copyright owner has assigned the copyright to the archive. Permission to reproduce this material must be sought before publication, even though, in some cases the copyright owner might be very difficult to identify.
However, you don't always need the permission of the copyright holder of published works (sometimes the publisher rather than the author, e.g. if you are using material from journal articles). Situations when you don't need permission are:
1. When you are directly critiquing or reviewing the material, as long as your use is fair dealing
2. For short quotations of text, as long as they are no longer than necessary to make your point and are all correctly cited
3. If the work is out of copyright (duration of copyright is usually for 70 years following the death of the author). NB this does not apply to unpublished works
4. If the work is released under a licence which allows you to reproduce it commercially, such as a Creative Commons BY licence
You will need to obtain permission from the copyright holder to use the content in all other circumstances.
Using images for book covers / event promotion
If you wish to use an image on the front cover of your book, or to promote an exhibition or other event, you must always get permission from the copyright holder to do so. If you intend to crop, distort or change the colour of the image (for example, adding colour to a black and white photograph), please ensure that you let the copyright holder know that this is what you intend to do. All of these actions constitute derivative works which must be cleared with the copyright holder before proceeding.