Ask for a sample of what he means
Maybe he and I use the term differently but I would not want to put my reputation on a painted luan.

It is a good deal. Poplar takes paint the best in my humble opinion or birch. Still with sealer, primer & filler maybe he can work magic with the mahogany? You never know until you see what he can do?

MDF for cheap painted
Birch for good

I find you need to double up MDF with the weight of the books Pif. looks good though I should put that project on my site. Nosed it & made the shelves 1 1/2... the customers didn't want to paint it, they liked the way it matched the spanish motif?