Polaroid type 55
Polaroid Type 55 film is a black-and-white peel-apart Polaroid film that yields both a positive print and a negative image (which can be used in an enlarger). Though box-rated at 50 ISO, the positive and negative parts of the film are effectively rated at 50 and 35, respectively. It is possible, however, to rate the negative at 32 ISO. Polaroid rates the negative at 25 ISO. When processed and peeled apart, the positive needs a protective coating, included in the box of film, to keep it from fading and the negative needs to be cleared in a hypo-removing solution (Kodak's Hypo-Clear works). Polaroid recommends an 18% Sodium-Sulfite solution. Polaroid also recommends using a hardening fixer to further protect the negative from scratches, but allows that it is not mandatory. The reason for this is that Type 55 negatives are very thin compared to other 4x5" negatives, and the emulsion is extremely soft.
Type 55 negatives are fine grained, have a long tonal range and are of extremely high resolution, around 150 lp/mm. They are useful for making large prints and for contact printing, especially in alternative processes such as Cyanotype and Van dyke brown.
Type 55 negatives are the famous source of the "Polaroid frame look". Due to the development process where a Polaroid 545 film back holds the film for exposure with a Large format camera, the Polaroid reagent/gel is squeezed between the negative and positive. Some of the reagent is trapped underneath the onion-skin-like frame that crops the print into a perfect 4×5 image. This reagent however creates an impression of that frame on the negative, which is not protected. The result is a perfect negative, but with imperfect frame-like image surrounded 3 of the four sides, while the 4th side shows the impression of the connective mesh that controls aspects of the Polaroid packet's sleeve functionality. This "Polaroid frame look" has been used extensively by many photographers who don't actually shoot large format, let alone Polaroid Type 55, but will scan a Type 55 negative in and superimpose the frame onto their other digital or scanned photos.
Polaroid Type 55, like all Type 50 series film, requires a Polaroid model 545 film packet Back. This Back is a device that loads the packet of sleeved Polaroid film sheet onto the back of a camera, most often a large format 4x5 inch camera. The same device is used to develop the film once it is removed, simply by pulling a lever into another direction and pulling the entire film packet out.
In February 2008, Polaroid announced it would cease production of all instant film, including type 55.
In 2009, Polaroid was sold under bankruptcy and the new owners announced that the process for instant film production would be licensed out to a smaller company, instead of being liquidated. Since the batches of chemicals needed to process Polaroid instant film were discontinued and stockpiled by Polaroid many years earlier, the licensees announced their intention to redesign and manufacture film on a limited basis under the Polaroid brand that would be compatible with most Polaroid film cameras, using machinery left over from a liquidated factory in the Netherlands.
In response, in November 2009, Polaroid announced its intention to relaunch the manufacture of Polaroid film cameras in 2010 on a limited basis, marketed to enthusiasts; contingent on the availability of the newly licensed film stock. Initial plans are to produce a black-and-white film to replace existing film stocks, followed by a color film.
Stocks of existing Polaroid Type 55 film are scheduled to expire in 2010.
A group called New55project, announced in November 2010:
With the news that there are no plans to produce any more Polaroid Type 55 P/N film a small group of Massachusetts tinkerers are starting to make their own instant negative films and processes. The goal of the project is to produce a new, very high quality instant 4X5 and 8X10 negative material to replace the no-longer-in-production Polaroid Type 55 instant P/N film.
This group is in the product development phase, and has demonstrated its own P/N film system. The final product if offered for sale to the public will be able to produce an instant negative using certain conventional 4x5 (and possibly 8x10) black-and-white sheet films. As of May 2014, New55 film has been successfully crowd-funded on Kickstarter, with production due to begin in January 2015.
- Polaroid Corporation. "Polaroid T-55 Film Data Sheet". Polaroid Corporation. Retrieved 22 April 2011.
- "The Impossible Project". (Licensee of Polaroid film products). Retrieved 4 December 2009.