Polaroid Image/Type 1200/Spectra is long discontinued, but it can still be found floating around eBay.
Far fewer people used Polaroid’s lesser known type 1200 format, alternately known as ‘image’ and ‘spectra’, which was marketed for use in professional settings. Image film comes in a wider format, giving one a slightly larger image.
The best thing about this film is its availability, as you can still buy it at the Impossible Project’s website for $22 a pack. It shows the same amazing characteristics as Polaroid 600 and is a joy to use. You can nab a Polaroid Spectra camera for less than the price of a single film pack on eBay, so if you want to use genuine Polaroid film, this is your best bet. Because it’s expired, there is occasionally a bit of a color cast, but it still looks fantastic.
See my Polaroid 600 review for details, but if you find a pack of this for a good price, don’t hesitate to pick it up. Good luck and happy shooting!