As Larry indicates, HC-110 concentrate is somewhat viscous. To me, however, it's not thick enough to cause any difficulty. I have mixed as little as 8 ounces of solution (1/4 ounce of concentrate for dilution B) with no problem whatsoever. I use exactly the approach described above by John Bowen. My graduate is a small plastic (Jobo?) which holds a maximum of less than an ounce. I also have some small measuring glasses I found in the housewares department at Wal-Mart. Except for being marked, they look like shot glasses and hold about an ounce. I've found them to be easily precise enough for measuring HC-110 and other concentrates such as T-Max, but I'll concede that they might be a bit tricky to use with a 1:100 Rodinal solution, at least for only a roll or two of 35mm. With HC-110 it's worth a little effort to work out a consistent method of mixing directly from concentrate, unless you process quite a bit of film and do it regularly.