I just realized that I have in my yet small portfolio around 70 seamless patterns, more than 30% of total images online.
I guess that makes me a patterner, as I keep seing patterns everywhere even when falling asleep (I know you all do to, photographers or illustrators, those images popping in our heads when we have no chance to get the real equipment to capture or draw it as we are half sleeping). With some luck, some are still there the next day, half forgotten or modified in our memories.
Back to the subject, I would like to add to the collection Seamless Backgrounds some of your suggestions. You can see the collection here.
They must be perfectly seamless on all sides.