After years of research (and several not-so-successful attempts) we've got the answer for large large format processing: the SP-8×10!
Simple: No frames/holders to fumble with in the dark. Just take the lid off and drop in your film. No seals, O rings or complicated mechanical contraptions.
Efficient: 500 ml of liquid, (actually, with most chemistry, you only need 300ml.)
Flexible: It will handle anything smaller than 8×10. Simple dividers keep smaller sheets separate. The production version will handle anything between 4×5 and 8×10: 5×7, 4×10, 4×5. Yeah, 9×12 will work too. You should be able to adapt it for those odd-ball sizes that no one else has heard off.
Convenient: After loading in the dark, all processing is performed in daylight.
Proven: tray processing has been around since, well, the first days of photography. It just works.
Download the user's guide here: SP-8x10 User's Guide
Intro video: Using the SP-8x10
NOTE: International orders will ship direct from our overseas warehouse for a flat rate of $22. Expect delivery in 10-15 days.
USA orders will ship from our Colorado warehouse at standard shipping rates (dependent on the service you select.)