<p>I am always fascinated to hear how many rolls of film people get out of these kits. I am surprised by the comments that they only last about a month. I mixed a kit last October (5 months ago) and it is still working. Last night I developed roll number 42. I've heard of people getting over 50 rolls out of a kit. Of course, eventually quality is going to degrade, but I honestly haven't seen that yet. The key, as mentioned above, is storage. I store mine in brown plastic lightproof bottles, in a dark closet, away from sunlight. I also make sure to get as much air out as possible before I put it in storage. </p>