Photrio(formerlyAPUG) is the a website and internet forum for an international group of photographers who use analog photography. The website was founded in September 2002, and has attracted approximately 60,000 members, including paying subscribers. The group's website is maintained through users' donations, subscriptions, advertising revenue as well as corporate sponsorship. 
The website's primary subject is Analog photography that involves using film and darkroom techniques to produce negatives, slides or prints. Subjects discussed in the forums are concerned with aspects of traditional photography, including processes like cyanotype, platinum printing and other alternative processes. Each subject area has a forum.
The galleries have scanned photographic materials posted, which concern the methods and results of traditional processes.
The website has an image gallery that encourages peer review.
The founder of APUG is Sean Ross from New Zealand.
Dick Arentz (born May 19, 1935) is an American fine art photographer and author, known for his textbook on platinum-palladium printing. Arentz's text book, Platinum & Palladium Printing, Focal Press. 1st edition (1999), 2nd edition (2004) “is known in online forums and industry magazines as the most comprehensive book on the subject.” Other photography insiders such as Dr. Michael J. Ware and Bill Jay have commended the author as a master-craftsman in platinum-palladium printing. Arentz has mentored other photographers in the platinum-palladium printing process by conducting more than 40 workshops for organizations such as The Center for Creative Photography, The Friends of Photography and The Museum of Photographic Arts. His work was displayed at over fifty one-man exhibits in museums and private galleries in the USA and Europe.