In the UK there are a whole range of museums and art galleries, many of which also have useful library collections to support their work, for example:
- The libraries at the British Museum
- The National Art Library at the Victoria and Albert Museum
- The Library at the Natural History Museum
If there is a museum relevant to your research contact them or look at their website to find out if they have a library and if you will be able to arrange access. Often the libraries of museums and art galleries are reference only with some restrictions on access, although exact policies will vary so you will need to check at each institution.