maybe you could substitute the white mahjong with the white coloured gloss art card.. I've used those for my model-making projects.. bought them in technical graphic shop..

they have them in various coatings (single-side gloss, both side gloss, both site matte, etc..) and thickness & size.. Last time I ordered too many of the wrong thickness, maybe I could make myself a lightbox for snapping macros..

Would glossy surface do any good to macro shots?