Probably because taped sides are a flag. Some of the complaints in this thread seem somewhat unfounded to me. Standard stealth shipping has always been printed labels, flat as possible / small as possible container, vacuum sealed product (sometimes in two or three bags). I am sure it can be improved upon some, most notably with less permeable vacuum seal bags, but if you are complaining about getting a few grams of powder shipped to you vacuum sealed between two sheets of paper in a priority mail envelope, you are really setting a higher standard than has ever been the the case. I have gotten international packages that consisted of powder dumped into heavily taped cardboard envelopes , that sounded like baby rattles when shaken , from the powder bouncing around all over the damn place. That is horrible shipping. Vacuum sealed flat in an inconspicuous envelope between two sheets of paper? What more could you really ask for other than that better bags are used perhaps? I note someone in this thread mentioned he thinks his package was seized because it was express shipped. This is very possible, in my experience I have seen far more express packages intercepted than anything else. Especially international overnight shipped packages are inspected in high percentages I think. Fast shipping is also a known flag for drug packages, the faster the shipping method is the more likely LE are to think the package is suspect and inspect it. Slower shipping has problems as well, like being in the mail system for longer, but I am actually pretty positive that slower shipping is less likely to lead to an interception. Maybe somewhere in the middle is best , but overnight definitely is the worst. Moisture barrier bags look like they all have metal foil on them. In general I would avoid shipping anything with metal foil on it if it can be avoided, I suspect packages containing metal are more likely to be inspected actually. I will need to read the thread about vacuum sealed bags first I suppose, but my initial thought is certainly that something creating a vacuum is far less likely to have scent permeate it than something without a vacuum. I also recall there was another vacuum sealing thread where someone with a drug dog tested several packages with different sorts of drugs, and the time spans for detectable permeation ranged from many hours to days, increasing substantially with each added layer of vacuum bag. Another technique I have heard people suggest is vacuum sealing the product in one bag, filling another vacuum seal bag with activated charcoal and then vacuum sealing it around the first bag. I have no idea if this is effective at preventing scent from permeating through all the layers or not, but I am positive it is effective at making the package weigh more. The more a package weighs the more likely it is to be inspected, weight is actually one of the most likely things to get a package selected for inspection. They are more interested in stopping big shipments of drugs than personal use amounts, and big shipments of drugs weigh more so of course they are going to be more likely to inspect a package if it weighs more. This makes me apprehensive about doing anything that will substantially increase the weight of a package, unless it is already quite heavy I suppose. Also, I have read in several profiling papers on drug dealers that the most sophisticated dealers vacuum seal their packages to prevent detection, it seems that if the most elite drug trafficking groups are using vacuum sealing that it is a legitimate technique, I have never heard of them using foil bags but I do have citations that they utilize mathematical / physics formulas to determine how long it will take for the scent to permeate their bags, to make sure their product is undetectable for the entire time it is in transit. So pretty much I think we should take the utmost caution when it comes to changing standard procedure for packaging things. Is there room for improvement? Certainly. There are all kinds of cool techniques as well, for example making pottery out of ketamine and then smashing it to bits and extracting it on the other end. People have done this with coke and they were busted because dogs could smell it , but for ketamine it may be a great way to move bulk. Vendors should really take care to change up their shipping methods somewhat as well, because they want to avoid being profiled. It is also really important for bothvendor and customer to understand the intelligence risk of checking tracking with proxy services, and weigh it against the benefits, and think of solutions that will work for them (checking tracking from home without a proxy is generally a BAD idea, but imo it is generally a bad idea to get shit sent to your house in the first place. Checking tracking with Tor from home on a package that is being sent to your home, is quite likely more dangerous than checking tracking without Tor on a package that is being sent to your home). Also a worry is that vendors use tracking stickers with sequential labels, and that an intercept of a single package sent out could lead to sequential serial numbers being flagged as well.