E-6 is the reversal process for color slide (transparency) film such as Fujichrome and Ektachrome. It requires dedicated chemistry and tight temperature control, so fewer labs offer it than C-41.
3 labs
2-43 Irie, Kanazawa, Ishikawa 921-8011, Japan
13-5 Oyamamachi, Kanazawa, Ishikawa 920-0918, Japan
2-chōme-83 Nishiizumi, Kanazawa, Ishikawa 921-8043, Japan