Shelf life of Lith developer

[Gerald Costello]

I have just started to experiment with lith development and am pleased with my initial results. I am aware that the solution once made up exhausts very quickly. My question is how quickly. I have stored my dev in an airtight bottle. Will it keep for a few days? I know it can be used to add to fresh developer to improve the lith effect but again how long can the used dev or 'old brown' as it is known be kept.

 

[Les McLean]

"Old brown" is added to fresh lith developer to speed up the ageing because the lith effect is more pronounced and considered better as the developer approaches exhaustion. Consequently, the age of the "old brown" is not an issue. I have had a 2.5 litre bottle of "old brown" for nearly 20 years that has never been emptied. Having mixed fresh developer and added the amount of "old brown" needed, usually 1 litre to 3 litres of working sol'n, I simply top up the "old brown" bottle with the near exhausted developer left in the tray at the end of each session of lith printing.

 

[inthedark]

About 50% of my business is lithography and I concur with Les. I will mix up a tank (5-10 gallons) of developer, then wouldn't you know I will get a void in lithography leaving the developer to sit for sometimes weeks or even a month without any real usage. Then in comes and order for 50 20 x24 plats. I find that so long as it is air tight during that time, the discoloring of the developer is insignificant. Since my tanks have to accomodate up to 50" wide, I accomplish the airtight by either pouring it into a 5 gallon collapsable bladder or overlaying the tank with sheet plastic depending on my need for tanks that day. I run five major printing processes but only have room for six tanks, so sometimes I have to pour off but usually not. Also it is interesting to note that old lith developer can be used to bring more contrast to multigrade b&w paper if/when using contrast filters isn't convenient or the contrast only need a bit of extra oomph. Anyway even with just the sheet plastic, it keeps nicely well into two months if not replenished and basically forever if it is.