>>55995803With Pokémon, they typically started off as dot art with accompanying pencil sketches if Sugimori's art for the Gen I Gym Leaders is any indication. Full standard art came later along with other illustrations. You can see Pikachu's design get refined a lot in the span of a year. The full Gym Leader art for Gen I and II only came with the TCG rather than the games. The Pokémon art typically appeared in promotional material until it was finally all shown in guidebooks. When Blue came out in Japan, all the art got updated to have more dynamic poses.
But for the anime, because you need to see the Pokémon from multiple angles, they needed to make settei like the one in your picture. Characters, Pokémon, objects, locations, are all detailed. Colors in hex, outfit details, things to watch out for when drawing the character like how bangs are parted, etc. This settei is sometimes shown to the public, but never all of it. In addition, the settei for existing Pokémon and characters are updated whenever a character gets a wardrobe change or their appearance changes like between series. Pikachu is clearly not drawn the same between 1997 and 2023. The settei for the anime is simplified compared to the games. You get a few solid digital colors and uniform lines compared to Sugimori's watercolor brushwork and linework of varying intensity. Often, designs evolved in response to requests from anime production staff and toy manufacturers. Something like Nidoking is more difficult to reproduce than, say, Marill.
