How much precum (Cowper's gland secretion) do you produce?

Five year update:
@Slippery... nice work. This is a five year update and I never collected a baseline value. Judging from the spot on my towel I guess the volume hasn't changed much (still in the middle of the curve approximating 1/4 teaspoon.) Of Aneros tools, MGX remains the tool that produces the "mostness" The big change with age has been the viscosity of my precum. It's rather stringy now. ... rook

I produce it in a continuous stream most times, especially when using an MXG. Love the stuff! Great nipple lube.

I’m 61 and the use of my Progasm combined with nipple play produces a good quantity of precum; a lot more than when regular masterbation. 

I'm 65 and have produced a lot of precum my whole life. If I'm horny and stimulated mentally, it starts flowing and I can get quite the wet spot in my shorts. Not surprisingly, during Aneros use I usually keep a napkin or paper towel handy to collect the continuous drips. What I do find interesting is that, if I masturbate after a long Aneros session (which I usually do), I don't ejaculate as much cum as during a "normal" j/o session. I am pretty sure this is because the prostatic secretions (precum), which accounts for most of the volume of an ejaculation, has been pretty much completely spent by the Aneros.

When I am really aroused I produce some.  Wish I produced more and everytime.  I enjoy sucking it off my wife fingers and nipples.

I produce a lot more now that I quit smoking weed and cigarettes. I used to play for an hour straight and not get one drop. Since I've quit smoking anything I play for 5 minutes and the faucet starts to turn on! If my wife is with me, it just starts pouring out of me. When I'm on certain drugs it pours out even more its a ridiculous amount it just keeps going and doesn't really stop for a few hours, even when I'm dressed and rolling/tripping, the precum starts running. During any prostate sessions over the last 2 years, I get a good amount of precum during them too.

It varies for me...sometimes its a ton, sometimes its not much.

I produce quite a good amount. Just being aroused it starts leaking.  Nipple stimulation by itself makes me leak a many drops. And I’m 64. 

It’s usually just a few drops, but I believe that’s more than enough to lubricate the urethra, which is the primary function of the Cowper's glands. However, during longer sessions, these glands tend to produce continuously. For example, I typically notice the fluid appearing at the tip of the urethra only after about 30 minutes.

I've had it range from shooting out like cum a few times, to having a 4 foot string flowing to the floor for upwards of 5-10 mins

It depends on what I’m doing. Sometimes just a few drops - other times a lot more if my asshole/prostate are being stimulated!