I core my tomatoes, just scoop out the area on top of the tomato where it was attached to the stem. I cut out anything that is not a red tomato. I do not skin them though. Most of my tomato canning starts with the tomatoes and other vegetables being buzzed in a blender. For juice, I liquify the tomato. For chili sauce, I buzz briefly to keep the tomato chunky.
Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has. Margaret Mead