# Look-up tables

The OMERO.server ships with a number of look-up tables (LUTs) for use in rendering images. These are stored under `$(OMERODIR)/lib/scripts/luts` in the OMERO.server and are managed in a similar manner to server scripts.

Admins can add new LUTs to the server by placing them in the `$(OMERODIR)/lib/scripts/luts` directory. These LUTs will be included in the list of LUTs available to clients via the API and can be chosen for rendering images.

The omero-web package includes a copy of the LUTs that are shipped with the OMERO.server in order to provide a “preview” image of each LUT. If you add new LUTs to the server, you can also update a cache of the preview images as described in the omero-web LUTs documentation.