Hi~! 0 u 0 I- I have a question! ´>///<`/ Why are you using the option "transp" with the wand? That is, what is the function of it? what is the difference in the selection? I use a canvas A4 size at 300 dpi, and if I make the step of selecting and then invert the selection to create a "base", that leaves me as result a base somewhat "pixelated" ... like without "anti-aliasing" It is understood? =///=Uu Thank you~!
The Transp bar is to adjust how much you want the selection to get over the lineart. The best way to understand is to try it yourself. Draw a something and try using the wand. The higher the Transp bar is, the more it gets into your lines. In case your lines are not really connected somewhere, a lower Trasnp would help you still select the part you want, but of course you'll need to fill it later mannually with a brush.
And for anti-aliasing, I suggest that after using the wand to select the area you want to fill, don't use a brush to fill it. Press Alt+Delete (Bucket tool) to fill it with your choice of color. Using a brush always make it pixelate despite the canvas size and resolution. It's just that if your canvas is big enough, when you zoom out it wouldn't show.