I always wonder just how it is that your drawings end up with huge filesizes, even if you didn't spend that long on them. Piles of layers maybe? I like the effect you have here, I may try to use it in a drawing I was planning if I can figure out how.
I honestly don't know. This one was only three layers. Marcello explained space use somewhere once but I don't remember how it worked. Something about .png and canvas size... I always use lots of brush strokes and transparancy but I have no idea if that has anything to do with file size. Which effect are you curious about?
I like how the glow looks like it has little sparks in it, like it has its own life. More than that there's streaks through the glow, not just a simple blend of color, and those three things build up to a very dynamic effect. Then, being on the cold blue background, these glows gain further life through their dynamic nature by resisting the cold and insisting on maintaining their identities. Each of these four groups in this image have become like their own beings, like some alien lifeform floating through space.
O.O you put a lot more thought into this than I did! ;) it started with a black background, then I added the blues with a low transparancy brush. I did the bright colors with the dodge tool... or the brush set on dodge, blurred it, went over it with low opacity and low "d" 1pt lines. then the airbrush with a "d" of 4 and went over it with an eraser with a "d" of 24.
drawn in 42 min