Once the surface is dry, punch in highlights with Permanent White Gouache (a water based paint similar to watercolor but more opaque). The sharper the transition and the greater the contrast (black to white), the shinier the beetle will appear. This is why the thorax looks shinier than the elytra (wing covers)..
I had to look it up because I can never remember this correctly, but “gouache” is how that’s spelled. Blame the French, it’s their fault.
Thank you! I will fix it.