Artist Comment:

シンプルに
saiの鉛筆ツールだけで。いや最近テクスチャ覚えてそればっかだったので

"Kept things simple, using only sai's pencil tool. I learned about textures recently and haven't been doing anything else."

Wouldn't "hadn't" work better? "Haven't" sounds like he's trying to make textures with the pencil tool, imho.

Yeah, makes better sense that way.