Graphite 002: Study of graphite on Fabriano Accademia Drawing Paper (200 gsm)

In this study, I examine how various graphite pencils and graphite sticks build up on drawing paper (Fabriano Accademia 200 gsm) using a simple usb microscope (magnified images) and a Near Infrared Spectrometer. Graphite 002 study is focused on Faber Castell 9000 series and graphite sticks. Future posts will cover other brands.

2.0   Materials & Methods

2.1   Materials

Graphite Pencils: Faber Castell 9000 set (2H to 8B, vegan-friendly)

Graphite sticks: Faber Castell Graphite Jumbo (2B)

Clutch Pencil: Faber Castell TK9400 (2B)

Paper: Fabriano Accademia Paper (200 gsm, vegan-friendly). The paper was fixed to a wooden board (30 x 42 cm, A3 size) as discussed my previous post in Mounting paper using staples.

Miscellaneous: A lid from Vöslauer Mineral Water bottle with an inner diameter of 3.1 cm was used to draw circles on the paper. A sheet of generic printer paper was used during the shading of the circles to avoid transferring any graphite from the test area to the surround paper surface. A tissue roll for blending the graphite layer prior to taking measurements with my Near-IR spectrometer. A Lab Stand with a clamp was used to hold the USB microscope or the LinkSquare Spectrometer. A mechanical pencil sharpener (Fig. 2b) was used to sharpen the pencils. An IPad Pro (12.9 inch, 2017 model) or an IPhone 5SE was used to take photos of the paper surface before and after shading.

2.2   Instruments & Software

Instruments: A generic no-brand USB microscope connected to an iMac, Infrared Thermometer (Broadcare GM320, purchased from Amazon), Linksquare Near Infrared spectrometer (Stratio Inc., website: https://linksquare.io/)

Software: USB microscope images were captured using PhotoBooth (MacOS native app), LSCollector (Stratio Inc., version 1.0.2) was used to collect the data from LinkSquare Spectrometer.

2.3   Methods

Step 1: Preparation of Work Area

I purchased a roll of Fabriano Accademia Paper (1.4 m x 10 m) from a local Art supplies store in Vienna, Austria. A large sheet was cut from the paper roll and using the method previously outlined (link here) I fixed the paper to a wooden board using staples.  I allowed the paper to dry for at least 9 hours prior to drawing or shading.  I rotated the board several times during the initial first hour to reduce one side becoming more hydrated and to stop any water pooling on the edges. The paper was allowed to dry at 25°C (room temperature regulated throughout this study). I checked the temperature using the hand held infrared thermometer at random times, and it remained constant. The resultant paper surface felt completely smooth and dry, shown in Figure 1.

mounted_fabriano_accademia
Figure 1: Fabriano Accademia Paper mounted on wooden board. The board on the lefthand side was used for this study.

Step 2: Shading circles

Using the lid (inner diameter of 3.1 cm), from my mineral bottle water (Vöslauer 1L) as a template, I drew circles on the paper surface using various graphite pencils and sticks listed in the Materials section (see Figure 2a). I applied diagonal shading in the circles using a “perceived” (see my discussion in Graphite Study 001) uniform pressure. Overall, the circles appear uniformly shaded (Figure 2b).

Graphite002_fig2
Figure 2a: Shaded circles on Fabriano Accademia paper (RHS) alongside pencils and graphite sticks (LHS).
Graphite_002_Fig2b
Figure 2b: Shaded circles on Fabriano Accademia paper 200 gsm using various graphite pencils and sticks.  (Please note in this post I will discuss Faber Castell graphite pencils and sticks, and future posts will discuss other brands later)

Step 3: Examining the paper surface using a generic USB microscope

The USB microscope was clamped on a Lab Stand to keep the height and setting consistent throughout this experiment. The magnification was set at least 20x (unfortunately I lost the printed calibration card, but that’s my minimum setting on the usb microscope). I will redo this experiment in the future with a calibration ruler. I connected the USB microscope to my iMac and used the in-built PhotoBooth app to capture the images. I chose an area within the circle with homogenous shading.  For blending I used a fresh piece of tissue each time and very lightly rubbed the area with it. I captured images before and after blend the circle.

Step 4: Acquisition of Visible and Near-IR spectra

Prior to taking the measurements with the spectrometer I blended the circles using a piece of tissue paper as described previously in Step 3.

I clamped the LinkSquare Near-IR spectrometer in a Lab Stand. The distance between the spectrometer and paper was approximately 0.75 cm. I used the test cards which came with the instrument and collected the data. I will use this data as my standard calibration data and note any variations in future experiments. The spectrometer was connected to my iMac running LScollector (Stratio Inc., version 1.0.2) and the data was collected. Both LED + Bulb were selected. Absorbance or intensities are measured as a function wavelength (range from 400-1000 nm). So far I have not processed the data but I will only show selected spectra collected without fixing the baseline. I have exported the raw data exported into Excel but I will come to this part in another blog post.

3.0    Results & Discussion

The circles appear darker with softer pencils (3B onwards) for Lyra, Brand Y (permission pending) and Faber Castell graphite implements as shown in Figure 2b. Looking closely at the shaded circles (Faber Castell 9000, graphite stick) using a generic handheld microscope (method detailed in Section 2.3, Step B) shows how graphite adheres to the paper. The images are shown below in Figure 3-14.

Figure 3: Faber Castell 9000 pencil grade 2H: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 4: Faber Castell 9000 pencil grade H: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 5: Faber Castell 9000 pencil grade F: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

 

Figure 6: Faber Castell 9000 pencil grade HB: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 7: Faber Castell 9000 pencil grade B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 8: Faber Castell 9000 pencil grade 2B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 9: Faber Castell 9000 pencil grade 3B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 10: Faber Castell 9000 pencil grade 4B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 11: Faber Castell 9000 pencil grade 5B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 12: Faber Castell 9000 pencil grade 6B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 13: Faber Castell 9000 pencil grade 7B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

Figure 14: Faber Castell 9000 pencil grade 8B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended (top), blended (bottom)

These results (Figure 3-5) show that shading with harder pencils (grades 2H, H & F) yields a more uniform layer both blended and unblended. I can also see that the particles or graphite clusters on paper appear to be smaller. It is possible that the smaller graphite particles enter the smaller valleys and dips in the paper giving a more homogenous-looking layer. As the pencil grade becomes softer it is clear the graphite particles or clusters become larger. When I blended the shaded circles there was a fair amount of graphite on the tissue paper which shows on the blended circles. For softer pencils (4B-8B) the effect of blending is more pronounced as shown in Figure 10-14, the large graphite clusters are broken down and spread across the surface of the paper. It is notable that shading with softer pencils shows a fair amount of white paper before blending.

Sel_FCall_Bulb
Figure 15a: Intensities of light plotted against wavelength (400-1000 nm) of selected Faber Castell pencils. The illumination source was the bulb (setting in the spectrometer). Pink (2H), Green (HB), Dark Blue (5B) & Yellow (8B)
Sel_FCall_LED
Figure 15b: Intensities of light plotted against wavelength (400-1000 nm) of selected Faber Castell pencils. The illumination source was the LED (setting in the spectrometer). Pink (2H), Green (HB), Dark Blue (5B) & Yellow (8B)

Figure 15 (a-b): Preliminary results from the LinkSquare Spectrometer. The data from this will be processed in Excel at a later date.

The results from the spectrometer show that with both sources of illumination (LED and Bulb, these light sources cover different ranges of the wavelength spectrum) the intensities of the shaded circles sharply drop as a function of the softness of pencil (more graphite or larger graphite particles). This confirms the visual images seen under the usb microscope (Figure 3-14). The x-axis in the Figure 15 is unfortunately not linear, but I will process this at a later date. But for this discussion it doesn’t really matter too much as these are comparative or relative results. What is interesting is that in Figure 15b, where the illumination source was a bulb (encased in the spectrometer) the difference in the intensities between 2H and HB is very large.  I will investigate this point in the future.

Here are the results comparing various 2B graphite implements: Faber Castell 9000 2B (previously shown in Figure 8) vs Faber Castell Jumbo Graphite crayon or stick (2B) vs Faber Castell TK9400 clutch pencil (2B).

Figure 16a: Faber Castell 9000 pencil grade 2B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended  (same as Figure 8)

Figure 16b: Faber Castell Jumbo Graphite 2B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended  (same as Figure 8)

Figure 16c: Faber Castell TK9400 (clutch pencil) 2B: Shaded circle unblended (LHS), 30x magnification (RHS) unblended

The magnified images of the various 2B pencils and graphite crayon in Figure 16a-c, show that although there are subtle differences in the shaded circles (LHS in Figures) the content of the graphite particles seems fairly similar. I thought that there would be some difference as the circle shaded with the graphite stick seems slightly darker.

Here are the spectra of various 2B graphite implements (produced by Faber Castell) on Fabriano Accademia drawing paper (200 gsm), shown in Figure 17.

bulb_2BFCclutch
Figure 17a: Intensities vs wavelength for various 2B pencils (Faber Castell 9000 2B (black line), Faber Castell Jumbo Graphite 2B (green) & Faber Castell TK9400 2B (red).  The illumination source within the spectrometer was LED. 
LED_2Bclutch
Figure 17b: Intensities vs wavelength for various 2B pencils (Faber Castell 9000 2B (black line), Faber Castell Jumbo Graphite 2B (green) & Faber Castell TK9400 2B (red).  The illumination source within the spectrometer was LED. 

The spectrometer was able to pick up the minor difference in shading between the 2B pencils. Slightly lower intensities were measured for the graphite stick 2B as it is visually apparent from the shaded circles (compare LHS images in Figure 16b vs Figure 16a and Figure 16c.).

4.0   Future Work

I will be undertaking a more detailed analysis of the spectra measured using LinkSquare for the Faber Castell 9000 and other graphite implements. I already have the studies for Lyra pencils and another brand (lets call it Y as the company would like to see my studies first before granting me permission to publish them on my website). I will also undertake similar work in the future on other drawing papers I have.

5.0   Permissions & Acknowledgements

I would like to thank Fabriano (E-mail correspondence with Giuseppe Prezioso, Marketing Fabriano, Italy) and Faber Castell (E-mail correspondence with Herr. Holger Unfried, Product Manager, A. W. Faber Castell Vertrieb GmbH) for their permission to show my studies.  Stratio Inc. clarified that I retain ownership of the data collected from the spectrometer. I have already signed an NDA with Stratio Inc. which has allowed me access to some information which I require for processing my data in Excel. Although for this post, only raw data is shown. Please note that I purchased all the art materials and I am not sponsored by any company or university.

Vegan art materials for drawing and sketching: a survey and study of resources available in Europe.

1.0 Background:

This article is a part of a series of articles in which I shall share my experience as a vegan-scientist learning to sketch and draw. Some articles will present my personal scientific research undertaken on my own art supplies. This first article presents a survey of the drawing and sketching implements which I consider cruelty free and suitable for ethical vegans/vegetarians. I will not be listing any products that I have not purchased or used. There are a number of websites and blogs that list the materials, but do not necessarily discuss their author’s personal experiences using them.

I will be presenting my experience as a student of drawing, sketching and painting with an understanding of chemistry and material sciences and trying my best to employ cruelty-free art materials (clothing, food, transport, etc.). When a broad range of cruelty-free and animal-friendly options are presented to me, I would opt for the most sustainable option.

2.0 Summary of my experience of finding vegan art materials (2017-9)

2.1 Starting point in 2017

In 2017, I decided to learn to draw and paint. As an ethical vegan, I have explored art materials available in the shops. I began with three major websites and blogs as a starting point to identify cruelty-free art materials, shown below in Table 1

1. www.veganwomble.co.uk Art materials are a subsection and primarily focused on art products available in the UK.

2. www.doublecheckvegan.com Art materials are a subsection and focused mainly on art materials available in the US.

3. www.veganartstuff.info Dedicated blog on vegan art materials run by Anja Hoffman based in Germany and focuses on EU supplies.  

Table 1: A list of websites and blogs which hold information on art materials suitable for vegans.

Although these websites and personal databases are very helpful as a starting point, however, I found them a bit unclear to work with. At times some products were listed as vegan on their websites, and after contacting the manufacturer, I found contradictory information. The reasons for this may be due to:

  • changes in production methods (switching raw material suppliers, or manufacturing facilities)
  • the expertise of the company’s customer service providers (a salesperson vs a technical chemist).
  • changes in company policies or changes in company ownership or restructuring.

2.2 Role of communication with manufacturers

At times some manufacturers I contacted did not fully comprehend the idea of cruelty free products and considered sustainability and cruelty-free to be synonymous. The most horrifying experience I had was with a company called “The Works” based in the UK who in response to my enquiries on paper sizing and glues used for making the sketchbooks, responded that “of course, it is made of paper (ha ha ha) and so you can eat it if you want to!!… “ This I must point out was in response to my query regarding sizing used for the paper, and if the glues used in binding could be free of animal-based raw materials. Following further enquiries they just sent me a legal blurb about their company policies which is identical to the one sent to Vegan Womble. Suffice to say, the understanding and approach of cruelty-free as well as sustainability varies from one manufacturer to another. Later on I shall summarise the personal impressions I have of each of the companies I contacted in the pursuit for finding graphite pencils made without animal-based ingredients and paper.

2.3 Influence of vegan researchers on the compiled lists

Another factor that initially I had not considered was the varying approaches and attitudes of the people who researched and then compiled the vegan-friendly art materials detailed in Table 1. This important and seemingly apparent issue came to light after I contacted Vegan Womble regarding  some conflicting information that was listed on their website and that’s when I realised that I had to undertake my own research and enquiries. There were some conflicting informations which was down to factors given in Table 2 below.

  1. How detailed was the questionnaire sent to the manufacturer? How do individuals or groups who compiled the questions communicate these to people who actually consult these lists.
  2. The definition of veganism, how it is interpreted, and finally how far should it be implemented. This of course is a very personal and a subjective factor.

Table 2: Factors influencing the variations in the on-line vegan listings

So I gathered that the researcher behind Vegan Womble used the definition set by PETA and used a simple questionnaire with the intention of keeping things straightforward and to include as many art materials as possible.  Personally, I am not happy with PETA’s approach to fighting animal cruelty by  overlooking protestors throwing firecrackers towards horse riders without due consideration for the welfare of the horse, and other approaches that I find so unbearable that I can’t write it here. I also did not get the impression that in-depth technical enquiries were sent. I am relating this experience not as critique towards Vegan Womble who I think are doing a great job at providing information, but more as a critique of myself for not really thinking about the differing attitudes towards cruelty-free and sustainability aspects people may hold. As a result of blindly following the list I unwittingly had purchased some art materials which I was later upset to discover contained animal-based raw materials. This was also in part due to my own misjudgement with reading cleverly devised replies from some companies which were not clear and could be interpreted in a number of ways. In the end, it was not Vegan Womble’s fault but all down to my unrealistic assumptions. This experience highlighted that I may be able to read and interpret technical information but I really have a long way to go to actually understand company policies or legal information. It has been a humbling experience.

Anja Hoffman who runs veganartstuff.info has a very detailed questionnaire and more stringent criteria that I agree with. She made me aware that not only should I research technical information but also the company’s wider policies on raw materials  and final product tested on animals, how tightly do the manufacturers regulate raw material supplies and would they be willing to communicate the changes to the customer (ie, change in status such as cruelty-free, sustainability, animal testing etc.). I hold her approach and honesty in great esteem, and I also thank her for highlighting the areas I ignored.

2.4 Decision-making process

Some manufacturers were very helpful and I felt had a better understanding of veganism, cruelty free and sustainability. Before I relate my impressions of the companies, I want to make one thing very clear, sustainability and cruelty-free are not interchangeable. Some products may be cruelty free but may not be sustainable, and vice versa. I would also urge anyone purchasing and using the art materials mentioned here to consider the factors stated in Table 2 and to use their own judgement by asking the manufacturers directly.

3.0 Survey of my vegan drawing and sketching materials

3.1 Vegan-friendly paper for drawing and sketching

In Table 3, I list vegan-friendly and cruelty-free paper that I use for drawing and sketching. Other papers for watercolour, oil and acrylic painting will be explored in a future article. Please note that I purchased these products personally and I was not given free products to review as some youtube reviewers and other individuals have done. My objective is to learn to draw and paint using cruelty-free, vegan art materials, rather than to become a reviewer.

Manufacturer Personal impression Vegan friendly products
Fabriano

Very helpful and friendly. They now have some products that are labelled (by themselves) as being vegan-friendly. I am very pleased with their support.

1. Fabriano Recycled Paper (200 gsm, 1.5 x 10 m, purchased from kreativ.de on sale for 19 euros current price is 28 euros)

2. Fabriano Designo 4

(Purchased from despar in Bologna, Italy)

3. Fabriano Artistico (1.5 x 10 m rolls of “soft” and “fine” texture, purchased from kreative.de on sale for 96 euros each)

4. Fabriano art journal A6 size.(purchased from a local art store in Vienna, Austria)

Hahnemühle

Very approachable and were proud to use novel paper processing which do not use animal-based ingredients. They are against animal testing and seem very genuine.

  1. Bamboo Mixed Media paper (265 gsm) 1.25 x 10 m roll for 65 euro on sale from kreativ.de.
  2. Bamboo paper A4 sketchbook (purchased from a local art store)
  3. Hahnemühle Skizzenblock Skizze 190 (190 gsm, 6 euros from a local art store in Vienna, Austria)
  4. Hahnemühle Technical paper 40 gsm (50 m roll for 9 euro from kreativ.de)
  5. Hahnemühle D&S sketchbooks (6 different ones purchased from a local art store)
Seawhite of Brighton Friendly and supportive. Eco Sketchbook (50 sheets, 130 gsm, cartridge paper, purchased for 6.38 euros from a local art store in Vienna)
Generic Printer Paper Printer paper (chamois or faun colour paper (one ream for 8 euros, 80 gsm)

Printer paper (chamois, faun 250 sheets for 8 euros, 160 gsm)

Printer paper (light grey, 160 gsm)

Best Point Helpful company and provided information needed.
  1. Best Point watercolour paper (unsized, 260 gsm)
  2. Best point sketchbook

(Purchased from Libro in Vienna)

Table 3: List of drawing and sketching paper used for studying sketching and drawing.

3.2 Vegan-friendly Graphite Pencils

“Not all Graphite Pencils are vegan-friendly!!”

Graphite pencils which are vegan-friendly were harder to find. Most art books and teaching resources lead us to believe that the softness of the graphite pencils is dependent on the relative concentration of graphite to clay, and that these are the only two components present in the pencil ‘lead’. So softer pencils such as 9B will have a higher proportion of graphite than a HB pencil. This simplified view is unfortunately misleading, as a combination of clay (earth mineral.. sounds “organic” and “earthy”, while actually they are mostly varieties of inorganic mixtures…) and graphite (a carbon allotrope, mined in the Lake District) which forms the heart and the essence of the graphite pencils encased in a wooden body makes the pencil seem like a product of the earth and benign.

Back in 2013, I purchased a set of Rembrandt graphite pencils produced by Lyra from an art shop in Graz. They are lovely. Later, I discovered woodless graphite pencils by Koh-i-Noor in 2017. I contacted both Koh-i-Noor and Lyra to ask if the pencils contained any animal based raw materials, and they stated they were animal free. However, after a few weeks of working with the Koh-i-Noor Progresso (woodless pencils) I felt a residue of oil or a fatty substance on my hands. Upon inspecting the surface of the paper using my usb-microscope I noticed the presence of fat globules. So I became rather worried. After searching on the internet, I stumbled across a comparable document sent to a customer enquiring about Caran d’ache graphite pencils, in which the manufacturer stated that due to the presence of tallow their graphite pencils cannot be considered vegan-friendly or cruelty-free. The reason for the addition of tallow (animal fat ) is to ease the graphite onto the paper surface. After these findings, I re-contacted Lyra and Koh-i-noor to reconfirm that the graphite pencil sets that I purchased were indeed free from animal-derived raw materials, such as tallow. Koh-i-noor finally told me that unfortunately the woodless graphite pencils actually contained tallow, and the concentration of tallow and the softness of the graphite pencil were directly proportional. Lyra on the other hand sent me a non-answer copied from their company policies but they honestly said they could not reveal either way. …  This was emotionally hard to take, as I felt that my trust in the companies seemed to be dwindling.

I contacted Faber Castell as their website states that except for 2 or 3 products (listed) all their products are devoid of animal-based raw materials. They were happy to confirm that did not use tallow or animal-based raw materials and tightly control and regulate the raw material supplies. I undertook my studies on the paper using my usb microscope and I did not notice large globules of fat even for a Jumbo graphite 9B crayon stick. I also contacted Anja Hofmann (mentioned previously) for her thoughts on whether the Faber Castell 9000 series can be considered vegan, and she said she was also satisfied they were, through her own discussion with Faber Castell.

I contacted Conte a Paris several times to enquire them about the Pierre Noire and Sanguine Pencils, however I have not received a reply. On various art forums, the impression I have is that Pierre Noire and Sanguine pencils are made from pressed ores or minerals and so are consider vegan-friendly. However, the same individuals also consider all graphite pencils as vegan-friendly as the graphite “lead” is composed of graphite and clay…. As these Conte pencils were a gift I will use them until they run out or hopefully I get a reply from the manufacturer confirming they are vegan.

For the drawings and sketches I primarily use Faber Castell products and Conte a Paris pencils too, as detailed in Table 4. I will use Lyra Rembrandt pencils for some studies as I still have them for comparative studies. I shall not replace them after they have been used up. I have already given my Koh-i-Noor pencils away.

Manufacturer

Product and Place/Manner of Acquisition

Vegan status

Faber Castell

9000 Series (4H to 8B) purchased from a local seller for 5 euros (second hand, unopened).

Confirmed Vegan

Faber Castell

Jumbo Graphite Crayons (2B, 4B, 9B) purchased from Boesner, Vienna

Confirmed Vegan

Conte a Paris

Pierre Noire HB, 2B, 3B

No confirmation

Conte a Paris

Sanguine, Medici, Sanguine XVII, Sepia

No confirmation

Faber Castell

Polychromos pencil Indian Red, Black, Ultramarine Blue, etc… (purchased a set of 12 from Amazon for 10 euros, other pencils purchased individually for 1.54 euros in Gerstecker or Boesner in Vienna)

Confirmed Vegan

Faber Castell

Charcoal stick set (willow), kreativ.de

Confirmed Vegan

Faber Castell

Charcoal PITT pencils (set of 3 pencils), Boesner, Wien

Confirmed Vegan

Derwent

Charcoal Pencil set (set of 4 pencils) a gift from a friend in the UK.

Confirmed Vegan

Faber Castell

PITT Pastel pencils (various colours), purchased individually from Mastnak Papier, Gerstecker and Boesner in Vienna.

Confirmed Vegan

Faber Castell

Castle series budget colour pencils (set of 48), purchased for 5 euros from Amazon warehouse.

Confirmed Vegan

Table 4: List of vegan-friendly drawing and sketching implements that I own and use.

3.0 Conclusion

Finding vegan-friendly and cruelty-free art materials for drawing and sketching was not as easy a task as it had initially seemed. Over this two year process, I understand that how we define and interpret veganism is very subjective and that it influences how we decide on what art materials to purchase and use. The vegan art material lists available online should be considered as a starting point but it is also as important to ascertain whether one (the end user) agrees with the ideologies and research approaches of the researchers (both individuals and groups) who compiled these lists. The approaches of manufacturers/ suppliers varied immensely with providing information. It is also important to regularly check the manufacturers’ websites to find any changes in the information and it is best to directly contact the manufacturer to confirm the vegan-friendly status of the products.

4.0 Future work

In the next article I will present an experimental (scientific) study of graphite pencils Faber Castell 9000 series on various papers (produced by Fabriano, Hahnemuhle, generic recycled printer paper, Bestpoint paper (local unsized paper)).