Our liquor cabinet has the usual row of holes drilled on either side for height-adjustable shelves, with typical shelf pins:
I think the wood is MDF + veneer. It might be plywood. It's not holding the pins very well.
The end result was sudden catastrophic failure followed by two hours of mopping up glass shards while trying to convince the world-famous Siberian husky who lives with us to stay in the other room.
Yes, that is a marble tabletop that actually got shattered into pieces by a bottle of Maker's Mark (recommended).
What would you use to reinforce these shelves instead of the dinky little pins?