I lack the artistic skill to make these more polished, but they express simple ideas of infinity (endless possibilities) perhaps encircled (like a globe) i.e ePub: the ultimate ebook format for the whole world.
There's the normal weight one, double infinity (also know as "
Rose of Four Petals"), as well as a thick one and thin one.
The last one, "thin double infinity", is a spoof of Adobe's .pdf three spiked logo!