I've never felt that there was a sheen to my 'Stained Glass' although maybe there is. My main garden pest this year has been EARWIGS, not slugs and they've done a number on some of my white-centred hostas.
The most recent pest problem of my 'Stained Glass' has been squirrels jumping from the oak tree above it and breaking petioles. Here's a pic of it taken end of June and most leaves appear

to have about 9 vein pairs. I'll go out after lunch and do an average count.
(Oh I see things have changed over here in the way we post pics. Possible to post more than on in a single message now?)
Ann