First step is simple enough, let us start out with a single color circle with no outlines what-so-ever.

• let us make a simple circle. If you were paying attention in the prerequisite course that i teach, "Basic Lines", making a smooth circle should be an extremely easy task at this point.

However, no matter how precise you make the circle, It looks rather "pixelated", even more so when blown up 300%. Our task is to make this circle look "Smooth", and we are going to do this by placing sequentially "lighter" pixels in those glaring jagged edges on the perimeter of the circle.

Using a slightly lighter tone, "cap" the edge pixels where you circle pixels meet the background (shown in pink). This is known as a "pixel buffer". Take an important note that we are not merely outlining the perimeter with a lighter colored tone.(areas not outlined shown in blue)

• So to start, we will pick our first tone, only slightly lighter in luminositu than the base color. We are going to make a first pass and "cap" the jagged edges of the circle's perimeter with these slightly lighter pixels. When you have one color that transitions into another color, only slightly smoothened out by "capping" those pixels, this is known as creating a "Pixel Buffer"

One important thing to note is that we are not outlining the perimeter, we are still leaving some areas where the darkest blue directly touches the ambiguous background color. The areas where this is evident, not including the "flat edges" of the circle, are illustrated here with these neon blue pixels. It would seem to make sense to just throw an outline around the whole circle, but doing so actually softens the image too much, creating an overly fluffy effect known as "pillow shading", which is a term to describe an image that looks light and fluffy, usually resulting in either successively lighter outlining of an object, or over blending of an object in general, using AA principles.

using an even lighter tone, you are going to once again "cap" the edge pixels where the perimeter of the outline meet the background. Because this has slightly deformed the circle, we added lines on the "flat" ends of the circle. Note that even this is NOT a perimeter outline.

• Our next step is to take another tone, even lighter than the previous one, and once again "cap" the left over jagged edges of the circle. 2 shades is usually more than significant to smooth out a transition from one color to the next (unless your object is a lightsource in itself, where some more AA might be required). However, doing this AA work on the circle has inadvertently turned it into a bit of a rounded square. This could be subverted in two ways. The first way is to pull in your dithering, inward to the center, or you could outline the "flats" of the circle to make the overall circle a bit more round, as illustrated on the left.

Note that the lightest shade actually doesnt blend into this background, This was done intentionally so you could better see the "capped" pixel effect. If i had done this in red to blend into the background color, it would have been a bit harder to distinguish what exactly was being done. So we have inadvertently created a sort of corona effect with our circle :) So now you know the technique used in the most basic of shading circumstances. Practice and practice well... and good luck ^_^. Actually... care to practice with me? Lets use this new technique in a practical application to turn this circle of our s into a moon.

our circle is now AA'ed from a light center to a dark background, using the technique you learned in the previous half of this tutorial.

• Our previous circle used an example that blended a dark circle into a light background. Now lets do the opposite, and color swap our palette entries in our previous circle example so that we are blending a light circle into a dark background. For this, we are going to face a light blue circle, into a darker blue sky background. Our AA buffer tones are going to fade from light blue to a purplish tinge, however, as they darken. These are some of my favorite colorschemes to use for nighttime sky backgrounds!

Moving on, lets start to shade the inside of the circle a bit so that the buffer tones used to AA the moon's perimeter begin to blend into the darker side of the moon. you can also do this on the lit side of the moon a bit with a light buffer tone to create a cratered appearance.

Add a new highlight tone to one half of the circle to create an illuminated half of your moon, and at the same time, add some darker details to indicate craters. Make sure that you are blending in all of your newly added details with AA.

• Next, we will Add a new highlight tone to illuminate the right side of the moon. Make sure that it is buffered by your previous highlight tone to keep the edges of the moon smooth. At the same time, we are going to use some of the darker buffer tones to define some deeper craters on the darker side of the moon. Make sure that when a dark area meets a relatively lighter area, that you have a buffer pixel in between the edges that they meet (and not the flat surfaces that meet) to smooth out the transition. That is, afterall, the whole point of this exercise.

Now let us add some cross shaped stars. Only blend them in on their x and y axis, this will create a twinkle effect. Note that the stars do not outshine the brightness of the moon ;). At this point, the moon's Critical AA point has been reached. Any further blending will make your moon look too fluffy, or "pillow shaded".

• Last, but not least, we are going to add some star effects, and using our new AA technique, we will blend a single dot into the background, but not in a circular pattern, but in a cross shaped pattern. Note that if you increase the saturation and brightness of the stars, and were to apply them to another situation, they make great "pixie dust" effects for spells and such.

One last thing to point out is the following. If you were to go ahead and use another darkest buffer tone to smooth out the transition even further from the moon to the sky, your moon will begin to lose focus, and it will look blurry. This i what i like to call an object's "Critical AA" point, in other words, a point at which maximum smoothness and sharpness is attained. Try it for yourself if youd like, adding another buffer tone around the perimeter of the moon will only make it blurry at this point. Take the current darkest buffer shade away and it might look a bit jagged.