What is different of Kraft Liner and Test Liner?
According to International Standard, Kraft liner consist 100% of virgin pulp, while Test liner only consist around 20% of virgin pulp. But in Indonesian, people usually say call test liner as kraft liner or all the liner as test liner.
Exactly kraft liner or test liner used for making the carton box. You can see at below picture, liner is the flat one and the wave one is the fluting or we also known as medium. Below picture is the double wall carton box. (red arrow is liner, blue one is medium).