The MK Unique Designs cast Acrylic call blanks turn very well use a sharp tool and When drilling inserts it is advised to use a cooling agent auto transmission fluid or WD-40, and drill bits specially made for acrylic. While standard bits can be used more care must be taken so go slow and take your time we will not refund for bad drilling or going two fast and breaking the blank. just take your time. these polish up great. And are fun to turn. make your own goose call or duck call.