Pencil Review: Non-Photo Blue Pencils

pencils with drawing

Review by Tina Koyama

Back in the day, graphic designers and printers used “non-photo blue” pencils. Certain shades of blue that could not be detected by camera film (or copy machines), so rough drawing lines or notations could be left on the art and would not appear in the final form. Modern scanners can see that blue, so non-photo blue pencils are not effective in the same way anymore. However, image-editing software can be used to manipulate the contrast or hue of the blue so that it can be made invisible digitally. Non-photo blue pencils still have life – but in a different way. (I’m not digitally geeky enough to explain further than that – heck, I still use Photoshop Elements to edit my images! – so I hope Ana will correct me as needed.)

Editor’s Note: You can scan an image that has non-photo blue pencil along with black pen and ink using the RGB mode. Then open the image in an image editing application like Photoshop and go to the “channels” palette. The blue channel will show your black lines and not your pencil marks but the red and green channel will not. You can select that channel,  make a layer, and fill with that data only. For a visual demo, check out this video.

I’ve never worked in graphic design or printing, and I don’t use sophisticated image-editing apps, so I had no practical use for non-photo blue pencils. Coincidentally, two people I am currently studying with both recommend the non-photo blue pencil, so I was tickled that this old-school tool has yet more life – this time in an analog way.

My first influence is cartoonist Lynda Barry, whose how-to books I have been voraciously devouring of late. (I don’t think cartooning is my bag, but I have been wanting to develop my imaginary drawing skills, and I love her approach to teaching.) She specifically recommends the Staedtler non-photo blue pencil.

The second influence is an instructor at Gage Academy, Kathleen Moore, whose subject area is about as different from Barry’s as you can get: drawing and painting nature. I’ve taken several classes from her, and in the current one using colored pencils, she, too, recommends a non-photo blue pencil.

Both artists use a blue pencil for lightly sketching the initial line drawing before inking (in Barry’s case) or using colored pencils (in Moore’s case). Their reasons are similar: While not invisible to modern cameras, non-photo blue lines are so subtle and pale that they tend to magically blend and disappear once the final medium is applied. In addition, lightly applied pale blue pencil is easily erased. Moore demonstrated another practical reason: If an initial drawing is made with graphite, almost all of it must be carefully erased before applying colored pencil. If any large particles of graphite remain, they could smudge, muddying the colors. 

With two respected teachers telling me I should get a non-photo blue pencil, I had no hesitation. In addition to Barry’s favorite Staedtler ($3.50), I also picked up a Prismacolor Col-Erase ($1.10), a contemporary Prismacolor Verithin ($1.10), and a Caran d’Ache Sketcher ($5.95). In my own vintage collection, I had an old Eagle Verithin, so I added that to the lineup. Although any light blue hue would probably work for this purpose, I stayed with ones that had “non-photo blue” (or “copy not NP blue,” in the case of the Col-Erase) in their names, just to simplify the options.

non-photo blue pencils

First, I tested them on my Col-o-Ring Oversize pad, which is slightly toothy. Erasing tests were done with a Tombow Mono Zero and a standard gray kneadable eraser. The second (scanned) image shows the differences a bit better, since they are all quite pale.

tests on Col-o-Ring

 Col-o-Ring tests scanned

Next, I tested them on a sheet of Strathmore Bristol Smooth paper, which has a very smooth surface.

tests on Bristol

 Bristol tests scanned

The Col-Erase is the palest and hardest, followed closely by the contemporary and vintage Verithins. Not surprisingly, the Caran d’Ache is the softest, which is true of most Caran d’Ache colored pencils. What did surprise me was the Staedtler, which was the softest after the Caran d’Ache. Most Staedtler graphite pencils are quite a bit harder than other pencils of corresponding grades, so I was expecting this one to be on the hard side, too. All erased easily and cleanly on both types of paper, especially with the kneadable eraser.

If I were making a drawing in which it was important for the initial lines to disappear completely, I would choose one of the Verithins for being a good balance between paleness and visibility – at least to this artist. The Col-Erase is easily the palest, but I can barely see it! If I don’t mind the lines showing, I would choose the Staedtler or the Caran d’Ache, since they are easier to see (and I generally prefer using a softer pencil).

For Mother’s Day, I felt like honoring my mom’s memory by making a drawing based on a photo that was taken in the late 1930s around the time that she and my father were married. I made the initial drawing with the Staedtler and remembered to scan it before I got too far with the final coloring with Prismacolors. I didn’t erase at all – most lines disappeared under my final coloring. In the small areas where the Staedtler lines are still visible, I could easily erase them, but I don’t mind their presence. Non-photo blue pencils for under-drawings are now a permanent part of my sketch kit.

7 - incomplete drawing with Staedtler lines visible

Incidentally, the drawing was done on Stonehenge Lenox Cotton. It was one of the papers in the Stonehenge Legion sample set I reviewed recently. I typically use Strathmore Bristol Smooth for colored pencil drawings, but I liked the Lenox Cotton sample so much that I bought a pad. Compared to Bristol, it has a light, fine tooth that takes colored pencil pigment beautifully.

completed drawing

tina-koyamaTina Koyama is an urban sketcher in Seattle. Her blog is Fueled by Clouds & Coffee, and you can follow her on Instagram as Miatagrrl.

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9 comments / Add your comment below

    1. I completely agree, Cheryl

      Tina, I love your mom’s hat. My mom always wore a hat to work before she retired and now to church, and I just love the way your mom wears here in this drawing.

  1. Tina, as usual, your reviews hit the nail on the head for me! John Muir Laws swears by the Prismacolor Col-erase for initial sketching marks. I have tried and tried, but I just can’t see that very pale blue. I have used any cheap light blue colored pencil, but they don’t erase well and sometimes too heavy of a line. Now I have other options, I think the Steadtler looks like what I should order. Hopefully in time for Wild Wonder Nature Journaling conference next week! Thank you!

  2. I am not a fan of the Staetdler but I do not remember why. I bought a box based on the strength of Barry’s recommendation but after a few tries, I moved on to other blue pencils and abandoned those.

    What i actually use more is a neon yellow colored pencil. It’s almost invisible against white, and also shows up very well on most other colors. I use them for tracing out things that I am painting, on top of whatever background layer of color I am using.

  3. This article takes me waaaay back. I used to use the NR Blue (also known as Cyan) when creating camera-ready mechanicals for separations for Litho printing in the ancient days. Also for all my pre-inking outlines for my pen and ink art. Every thing was manual then, even to the masking areas for spot color separations (rubylith and amberlith mask cutting required a sturdy arm, fluid shoulder and a very precise touch). Anyway, glad to read there is still use for the NR Blue, kinda gives me hope for myself

  4. finally someone gives actual info about the col erase. it would have saved me alot of time and effort if this post came out years ago. Basically i bought NPB colerase since i was told there was a shortage of the blue i always use for preliminary sketches. Idk at the time I first bought it from my animation lecturer he told us its NBP but apparently its just normal blue.

    anyway the NBP pencil…NOTHING and I mean nothing came out. I was just basically leaving indentations on the paper with the sharp tip of the pencil. nothing no line was seen on the paper… I sharpened and sharpened wasting my very exp pencil wondering WHY and searched all over internet and many people talked to me like I was dumb and did not know what NPB pencil was/ what it is used for. Even the shop was rude and thought I was stealing my own purchased pencil from them when I went back to try and get a refund thinking its old stock (i have had old pencils that cannot colour anymore)

    Its been sitting in my room unused for at least 3 years now 🙁

  5. Thank you sooo much for this excellent comparison! I have just come across John Muir Laws’ recommendation and was trying to find some further information. Very scarce and most people just trying to pass off any ordinary light blue pencil which is definitely NOT the same thing!. Again, lovely to find an informed – and complete – post. Many thanks.

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