Ah... Paper towel!
I would like to see the same tests performed using a double edge (DE) razor blade. A DE razor is often used as a control standard for BESS testing as they are very consistently around 50 cN for most makes. The Feather brand is a bit sharper.
The condition of the edge of that knife is an obvious and significant variable. Testing with a DE blade would help to ameliorate and mitigate those concerns.
I would like to see the same tests performed using a double edge (DE) razor blade. A DE razor is often used as a control standard for BESS testing as they are very consistently around 50 cN for most makes. The Feather brand is a bit sharper.
The condition of the edge of that knife is an obvious and significant variable. Testing with a DE blade would help to ameliorate and mitigate those concerns.