These images are created from Polaroid 665 Black & White Film (no longer manufactured). The throw away portion of the shot is saved and processed in Sodium Sulfite which creates a negative that can be printed in a dark room format. The final images have an aged look to them and can be very exciting. The process is very tricky and with the film being very rare you need several images to have a final copy.
Bromoil is an alternative photography technique where the black and white print (made on special paper) is bleached to remove the image. Then, stiff printers ink is used to bring the image back as the ink deposits into the areas where the original print image was.