Old school deadhead here, I can shed some light. Pure/crystal LSD usually comes in vacuum sealed vials, most commonly obtained by the gram. On average, one gram is enough for 10,000 standard doses. (10 10-packs). To lay on blotter paper, you (very very carefully) measure out 10'ths of a gram, which is 1000 hits, or a "10-pack" and use at least 151 proof alcohol to dissolve each 10th in alcohol on a tray. You experiment with the alcohol and the tray ONLY (prior to opening the vial of product) to figure out exactly how much alcohol the blotter paper will absorb. Once you figure that out, dissolve the crystal into the right amount of alcohol, and on a perfectly flat surface, you gently lay the paper in the tray and allow it to soak up 100% of the liquid. Let it sit for a few minutes. Then, using tweezers, carefully lay the blotter flat on a table to dry, usually on wax paper. Double dipping would actually skew the amount in each dose, and make the dosage dangerously unpredictable. As far as exact amounts of micrograms per dose, never had a clue. If you want stronger product, you'd make 9000 doses out of a gram, or weaker, make 11,000. Quality was determined by the grade of LSD you had, which usually can be determined by the color of the product. I have seen silver, amber, white, even some stuff that was little balls like gunpowder. White was usually the best quality. On a side note, when the work is finished, you can use leftover blotter paper, or just about anything to make "mop-up" by washing all tools/surfaces that were used and "mopping up" the mess. Mop-up is technically "double dipped" but mop up was very rarely sold. Back in the day, (in Grateful Dead land) we always just used our ticket stubs from the night before for mop-ups, that way nobody but you knows what it is and we could have our personal stash without risking getting busted, since it was a pretty sure bet that everyone in the crowd had at least one ticket stub in their pocket. Anyways, my point is, at least in my experience, double dipping is counter productive, it is all about ratios. I'm sure there are other/more exact ways to accomplish this, but this is pretty much what we did back in the day, with the simple tools we had. All that's really needed is a scale that accurately measures .1 grams, a bottle of Bacardi 151 (or moonshine) and a small spoon or blade. Usually the hotel already had the perfect little plastic tray, or you'd just use a pyrex baking pan. So, IME, "double dipped" is a myth, it is all about ratios.