full of bees, pollen, brood, or honey? last year they were new so as they drew out the frames they became full so it was easy to tell how full they were. but this year i have all drawn out frames so it kind of hard to tell how full they are.
I think Wally was giving you the answer for undrawn foundation. If you have drawn comb and are looking to super up for the flow I would think you could put the super on now as long as it was not brood comb before or you have enough bees or other wax moth precautions to prevent comb damage if the bees don't show an interest in the super just yet. I have seen where other beekeepers may put several supers of drawn comb on a hive in anticipation of the flow so that they don't inhibit the bees filling them up when the flow starts. If this is what you were asking about, I hope this helps.
Go through the frames. If you have 6 empty frames of drawn comb, don't super. If most frames are full, "of anything", then super. If you have supers of drawn comb, you can put 2 on. If foundation, 1 only.