3 ms·

If you soak the entire sheet, I don't think you can be certain how much active product a single blotter absorbed

• __MatrixMan__ 3y ago
  But with the make-100-droplets technique, how can you be sure that each droplet contains the same amount? You're still relying on diffusion of solutes to achieve some degree of uniformity across several fixed volumes.
  • nicd 3y ago
    Diffusion in liquid is relatively consistent. When paper is soaked and allowed to dry, it can produce uneven concentrations as regions evaporate at different rates, and solutes move along with the flow of solvent. A good example of this is water color painting: if you mix paint into water and then apply it to the paper, the resulting patterns may be less uniform than when applied.
    • __MatrixMan__ 3y ago
      I see, thanks. I guess drying is essentially crystal regrowth, and the thing about growing crystals is that the material concentrates around the nucleation sites and spoils the nice even distribution that you get from being in solution. Seems like one can expect a hit to be a more precise dose than a half-hit, presuming it's still done that way.