Texture file node with the <udim> tag
A tutorial that shows how to use the UDIM texture token can be found here.
Ensure that you use absolute path names when using the <udim> file token. For example:
'textures\my_colours.<udim>.tif'
textures\my_colours.<udim>.tif'
becomes:
'C:\Users\Documents\projects\Udim\textures\my_colours.<udim>.tif'
C:\Users\Documents\projects\Udim\textures\my_colours.<udim>.tif'