thanks Beema and Noni for your speedy replies!
we've been comping since birth - what with emergency c section, gestational diabetes, and breast reduction surgery, plus I think a general lack of education, it seems like I just may not be able to get as much milk as I would like. I have spent time with two excellent LCs (including Pink Mackay), and they agree that this may just be the way it is for us. Zac's attachment is excellent so that doesn't appear to be the problem.