The one I was thinking of was the Asterion one, yeah.
Basically the way sprites were set up (a simplified explanation) was
- A layer with the fur as a solid color and all the color details like Asterion's muzzle and nails
- A face layer, with facial expressions
- A lineart layer, which included the shading done in black and white
- Then all the clothing layers on top
Now this had two big disadvantages: 1) Shading with black and white (as opposed to using desaturated colder hues, and warmer hues with higher saturation, respectively) looks fucking terrible and I have no idea why I did that for years and 2) since the clothing layers have to go on top of the expression layers and the lineart layer is fixed for each pose, Asterion's muzzle was set at a fixed position. So if I wanted him to open his mouth to laugh, the muzzle would still be as wide as it was when his mouth was clothed, which doesn't look great. It severely limited his expressions.
So, after doing that revamp, the layers are set up like this:
- A layer with the fur color and shading, this way each fur color has specific shading and lighting colors (eg. brown has a more saturated orange for lighting and desaturated reddish purple for shading)
- A layer with all the lineart and details in one
- A bunch of the clothing layers like neckwear and upper body clothes
- The face layer, which includes the edge of the muzzle. This way the mouth can go over the upper body and neckwear layers and Asterion's muzzle can change shape easily
- The rest of the clothing layers
And... I had to revamp all of those, 4 times, one for each of Asterion's poses, and modify some of the clothing sprites to accomodate for the missing space where the muzzle used to be. Well, 4 and a half considering that Asterion's arms change on the pissed off sprite and the surprised sprite. And all the faces were redrawn to fit my current more expressive style.
So yeah, you can see why this one makes the top 3.