We also buy our Oplatek at the church or a religious store.Some of the Polish Deli's here in Chicago also sell them.
Must tell you about the ultimate Christmas gift I received from from (adult) grandson.He is in California and unable to come home for Christmas this year so will be celebrating Christmas with a few friends.He called yesterday to ask his grandfather where he could buy oplatek...he explained he has gone to numerous grocery stores and no one has heard of it!
Our grandson lived in Maryland with his parents who no longer attend church...they only celebrated the Polish traditions when we visited every second year, during Christmas....therefore I was totally surprised that one of the things he wanted to celebrate and introduce to his friends was the breaking of oplatek.
I am disappointed that the only kind of oplatek we have found here in Chicago are the thicker wafers.A few years ago I was able to find the very thin. crisp wafer as well as the small wafers to enclose with a Christmas card.