Do I need to seal unglazed PEI 5 porcelain

[Filip]

Ok thats the end of the water absorption test because after 24 hours I want my pint glass back.
Result - no weight gain.
2nd result - beer for me

 

[Filip]

Ok I have now done a grout test and that is fine, infact nothing seems to stick to this tile, I do actually need something to stick to it - namely adhesive. So I have done a grout test on the back and that is a lot more difficult to get off. Picture attached. The tiles are marked on the back Made in Turkey - is that good ?