Paper Smoothness/Roughness

[SteveSuffRIT]

Hello PrintPlanet,

Do any of the paper people have any data they can share about this?
Ra is a metric of surface finish and its unit is 1 micron (um).

 

[SteveSuffRIT]

Also, a visual would also be great to support it.

 

[Stickman42]

What kind of info are you looking for? I had some grades of paper tested by Oce/Canon’s lab years ago, to determine compatibility with the laser printers I was running at the time. As a book manufacturer, our clients asked for groundwood. Some of them were out of their spec in the Sheffield (smoothness/roughness) category. I may be able to find the reports with some digging around.

 

[SteveSuffRIT]

Hoping for data from a contact profilometer (diamond tip stylus) that shows X-height variation over distance.
Provide numeric value of Roughness with Ra value, in microns (um).
Sheffield uses escaping air flow (porosity) through paper fiber pores.
An X/Y scatter diagram of that vs Ra would also be interesting.
An X/Y scatter diagram on Gloss vs Ra would be nice.

 

[SteveSuffRIT]

"Ra" roughness value is provided by an instrument called a Profilometer.
Some can also provide the topography profile curve.
Most printers probably don't have this, but paper and blanket mfg should.

 

[SteveSuffRIT]

PDF of PowerPoint handout notes on "Ra" Roughness