I noticed Houdini has free textures you can download as .rat or .tif formats (https://www.sidefx.com/get/download-houdini/free-textures/ [www.sidefx.com] ). I can't seem to find any help on installing the .rat materials and was hoping someone could show me what folder in Houdini 17 you would copy these files into to use them (or are the .rat format materials already included in Houdin 17)? I get that the .tiff files are for customising in PS or Gimp etc but not sure what to do with the .rat material files. Cheers.

the rat file format:
http://www.sidefx.com/docs/houdini/io/formats/image_formats.html [www.sidefx.com]

they are just images.

Thanks