No Suction Bath Mat How To Make My Bath Tub Non-slippery?

How to make my bath tub non-slippery? - no suction bath mat

I bought several types of bath mats with suction at the bottom does not stick even after leaving the bath mat in place, and I do not use these little wall in the form of various species of marine animals. Who knows, or have no idea how to make it a smooth tub differently. Glass or something appears and with what?