Hi Val....the ultimate way to get a definitive answer to your exact density figures for your crown etc. is [ I suggest] make your template as suggested -and yes those are flaps at the side..many wear them..Swiss lace is the ultimate in invisibility if that`s a concern for you but it will be that bit weaker at that point as I said..you might need a little extra durability there--- have your template ready and then have a web-cam consultation with Debbie..... she`ll put your mind to rest and will advise on how much density to order which you can mark on the template with a marker in the various areas.....Tapes are extremely thin.... at a guess..about a quarter of a millimeter .. hardly worth `bothering`about ...... your observations on low-density being `pushed`here is valid but what you got to take into account is you/your hair is the exception rather than the rule ....you`ll need higher density than most of us.... it`s not a `one-size -fits -all` rule but generally it holds true and most people cannot carry off high densities...... I`d really consider a consult with Debbie .... you get an allowance off your first order too so it`s a good investment really.... cheers.. Paul.