I had some issues with MerckKGaA due to some shoddy stealth, but he made up for it (greatly) by shipping me an additional 5 grams of MDMA. All reagent testing showed both samples were uncut (I tested with marquis, mecke, and mandelin), but I wanted to of course I wanted to know apx. purity levels. I also wanted to use two different test kits in case they were two different batches. I sampled the average color using photoshop, and also matched it with the closest color. I spilled a tiny bit of my sample in batch 2 but I don't think it affected the overall outcome. I would rate both at highest tier purity, although it looks like sample 1 is ever so slightly more pure. I've attached photos below for your review:
tl;dr: Tested 2 MerckKGaA MDMA samples, both came out higher than 75%, although one sample was slightly darker than the other.
How can you test purity with testing kits? Even with a reference standard?
They can only tell you if something is in there. An inactive cut wouldn't show.
You shouldn't guess at purity levels, even if you owe the vendor a favor. You're not doing him any favors, particularly with all the "MerckkGaA is a scammer" posts doing the rounds.
You tried to make a load of complaint posts yourself, didn't you?
http://www.reddit.com/r/DarkNetMarkets/comments/33pyae/complaintwarning_merck_do_not_order/