Among Consumer Reports' reminders to photographers who send their film away for processing:

* Film is less likely to get lost if name-and-address labels are affixed securely to the film container. (Kodak advises against using gummed address labels.)

* If film is lost, it may turn up in the lab's "lost and found" and you stand a good chance of getting it back if you can describe the pictures in enough detail.

* If you use a mail-order lab (where you prepay for developing and printing) and are dissatisfied with some of the prints, you should ask for free reprints or a refund.

* When you return unacceptable prints and negatives for remakes, point out why you're dissatisfied ("background too dark," "colors not true").

* Pre-printed mailers offering "priority handling" for a nominal extra charge don't necessarily mean faster service.

"Problems with pictures aren't always the processor's fault," as CR points out. Besides being sure of the obvious problems like focus and exposure, you should:

* Handle film carefully when making photographs. Unexposed and exposed film can be damaged by: high temperature, high humidity, "fumes from mothballs or from perfume spilled in a purse."

* When ordering reprints, handle negatives carefully. Don't touch the part of the negative with the image on it and do not cut the negative strip apart. "To identify the picture, use the frame numbers on the film."