The New 52 Batman Wiki

The Bleed was the area in between universes that held the Multiverse together. Due to it's unique proximity, it allowed Stormwatch to command the Carrier through it with ease, making them perfectly invisible to their enemies. Few other Stormwatch could traverse the Bleed, although travelling through universes did mean crossing the Bleed, those who did usually only were in the Bleed for a split-second. There were many ways to access the Bleed, with Stormwatch doing it through the Carrier and the heroes of the House of Heroes doing it by going at different frequencies. The Orrery of Worlds, which was located inside the Bleed, had fifty-two different universes that each existed at different frequencies in bleedspace. As such, existing in the Fifth Dimension, bleedspace was a fluid-medium which managed to hold the Multiverse up inside the Source Wall.