This patch at the top or on the side of the photo is caused by uneven spreading of the film emulsion within the image.
This problem can be caused by roller pressure in folding type cameras, which varies from camera to camera and the viscosity of the film emulsion.
To avoid this problem with folding type Polaroid cameras (SX-70 or SLR-680), you can add slight downward pressure to the latch of the film compartment of your camera while the image gets ejected from the camera. This slightly increases the roller pressure and ensures even and complete spreading of the film emulsion.
If the undeveloped patch is on the side of the image, the problem might be caused by a bad storage of the film or a defective film.
If you need more information, please contact our customer service at firstname.lastname@example.org and attach some scans or digital images of your pictures showing the issue. Please also specify the number on the back of the picture and your order ID if you have ordered on our online shop.