Sunbabies Question

Hi! Just got my order of Sunbabies diapers in today! :) So adorable! I'll have to take a fluff pic of DD!

Anyway, question for you all - maybe I ordered wrong, but there are 6 inserts of one type and 6 inserts of another type. One feels/looks like microfiber, but the other is smoother. Anyone know what they are? I feel really dumb asking this, but all the diapers I've had so far were microfiber inserts!

TIA!

I got these too with my last order. She was offering a free upgrade on some of the diapers for awhile. I'm pretty sure they are bamboo, but I thought it was a little weird...one of them was thick and fluffy and the other 2 are thin and flat.