For quite a while I’ve been planning on having a closer look at how different paper performs for pencil use.
I think it started because I loved the County Fair Field Notes I got from Koralatov, but when I tried the Original Field Notes (FN-01 to FN-04) I didn’t like the paper at all. (According to the text in the back the County Fair edition is using Boise Offset Smooth 50#T paper, while the Original version is using Finch Paper Opaque Smooth 60#T.)
Well, I thought I better have a closer look. Long term, i.e. if this is of interest to readers, I plan on also measuring how abrasive the paper is, but I haven’t found an easily reproducible way of doing that yet that can be measured accurately, so I am focussing on how dark a line the different papers will produce with the same lead.
Following Kent’s post about the Lumograph being a good standard pencil, because it is good, not expensive and available world wide, I wanted to use the Lumograph, but for several reasons (I don’t want to bore you with them) I went with the next best alternative: Staedtler’s mechanical pencil lead.
Violin plots showing the distribution of darkness of the marks left by the lead on different papers
I try keep it short, but more details are available if there is interest.
Force used: 1.5 Newton (roughly equivalent to 150g)
Lead used: Staedtler lead, 0.7mm, the one that came with the Mars micro. I assume it is HB, but I have added a Staedtler 0.7mm HB lead to a recent order from The Pen Company, so that I can use those leads for future comparisons.
Pressure used: 4.17 MegaPascala
As seen in this blog post a 0.7mm lead has a diameter of 0.68mm, that’s a surface area of 0.36mm2. That’s a force of just over 4 MegaPascals. The equivalent force used on an 0.5mm lead to produce this pressure would be 1 Newton.
I found these parameters to be a suitable trade off between force and diameter size. More force means more problems with me providing consistent, reproducible results. The obvious way out would be to reduce the lead size (= more pressure per square mm), but a smaller diameter means measuring the lead’s darkness becomes more difficult and less representative.
Notebooks used for the comparison
Some quick comments on the paper.
Great and extremely dark for pencils. So unusually dark that you can easily switch to a harder pencil grade and get a similar darkness compared to other paper. My wife started using an H lead for writing in Atoma notebooks.
I did a control sample to confirm that the plot shown in the diagram is correct.
As always great paper! This is the latest generation of Banditapple paper: 4G, just released.
Very common in the UK. Most Post Offices will sell Silvine products, but unfortunately the red Memo Books have become a rare sight. Silvine is planning to revive their red notebooks.
Used in County Fair Field Notes. Great paper.
Very light and smooth paper. I expected a smaller standard deviation. The notebook used is a handmade notebook from Shangching, previously seen in this video.
Used in the Original Field Notes. I don’t like it for pencils. I should probably switch to using softer pencils in this notebook, then this paper might be alright. Also not good for fountain pens.
Box plots including two control samples on the right
The diagrams show the distribution of dark and light marks left by the lead on he paper.
I first planned on using box plots. I have heard that they even teach box plots in school these days, but I went with violin plots instead. violin plots are basically box plots with a rotated kernel density plot on each side. I thought this provides more information, compared to box plots, in the same space.
I have taken samples of exactly the same size from the mark left by the pencil on all these papers. In the diagram 3.0 represents white, 0.0 represents black, so you can see the distribution of dark and white in the mark left by the lead on the paper. A darker mark, like the one on Atoma paper, will show as a plot further down (closer to 0.0) in the diagram.
Smoother, finer paper should produce less variation, i.e. a more even colour, so the plot should be more condensed. Rougher paper should have more ‘peaks and troughs’ on the surface, so the darkest areas should be darker and the lightest areas should be lighter, resulting in a stretched plot.
There are two control samples, only visible in the box plots. They are taken from the cover of Field Notes Byline edition. They are just used to see whether using different samples in different scans will produce close enough results in the plots.
Where to go from here
If this is of interest I could look at the different types of paper used in different Field Notes. I could put the R code used to produce this on GitHub. I also have a great paper sample pack from Scribble I could have a look at. Long term the darkness could be plotted against the abrasiveness of the paper.
If there is at least one comment on this blog post I will continue exploring paper, if not I will write blog posts about topics other than paper that might be more interesting, e.g. pencils.