I'm comparing these "EasyClose" envelopes to the "Sustainable Earth" security envelopes of the same size that I already have also by Staples. Both are adequate paper weight (these are a bit heavier--24 lb. vs. the 20 lb. of "Sustainable Earth"). It appears the glue however on the "EasyClose" is stickier and the crosshatch security pattern on the inside of envelope hides better under lighting than the cheaper lick-to-seal version of "Sustainable Earth". The only improvement I'd like to see in the "EasyClose" version of Staples envelopes is a longer line of glue so the flap ends don't go uncovered for about 3/4 inch on each end. I don't want the envelope hanging up in the automatic postal machines. The "EasyClose" type do cost a little more but worth the price difference to me.
These envelopes are just as good as any of the major brands out there. They are thick enough that they cannot be read through. I mostly like that they are the peel and stick kind instead of the lick and stick:) I needed these and happened to find that they were on sale. I also had one of the coupons that staples sent me so I got 100 envelope for only 3.00. Will definitely buy these again. And I will recommend them to anyone who asks me about them.