Monday, October 12, 2009

Uni Nano Dia Mechanical Pencil Leads

Uni Nano Dia Mechanical Pencil Leads

Earlier this year Japan’s Mitsubishi Pencil Company released their new mechanical pencil leads, Uni Nano Dia. As far as I can tell, basically their claim is that by mixing super small carbon based nano-particles (so called “nano-diamonds”) into the lead formulation, that friction will be reduced thereby creating a strong uniformly dense, dark, smooth writing lead with reduced wear. Diamonds...sounds great. Well then, let’s check these Uni Nano Dia leads out.
uni nano dia lead refills
uni nano dia diamond jewels
Uni Nano Dia leads come in a range of diameters and hardness grades. Currently in 0.5mm they come in 4H through to 4B, including F. I think they only have the one grade of HB, not the other two grades of HB that some Japanese brands offer.

The lead tubes are colour coded by hardness grade in very bright attractive transparent coloured containers. There are 40 x 0.5mm leads per container. The top slides to the side to let you get the leads out.
uni nano dia lead

Right then, time to put lead to paper. Currently Pentel Ain are my reigning champion of leads, so some comparison against them is obviously called for. Please remember that I am testing these leads by hand and by eye, so the results are highly subjective. In order to try and minimise the human factor I am conducting repeat trials, and they are blind tests in that I don’t know which lead is loaded in which pencil. Two Uni Shift 0.5mm mechanical pencils were used for all these tests - oneloaded with Uni Nano Dia 0.5mm HB and the other with Pentel Ain 0.5mm HB

First up, lets try laying down some lead and erasing it. Below is the test card, with Ain and Nano Dia erased by Staedtler Mars Plastic, Pentel Hi-Polymer and Faber-Castell PVC Free erasers. Effectively there’s no significant difference, perhaps the slightest hint of a little smearing with Nano Dia but basically it’s a dead heat.
uni nano dia + pentel ain erase test

Next then test for smearing. For some artistic purposes you might want a lead to be smearable, but for normal writing purposes I believe most of use a smear resistant lead. Again, as you can see below it is close, but I think Ain was a fraction more smear resistant.
uni nano dia + pentel ain smearing test

How about blackness. Well, both are quite similar in their darkness.
uni nano dia + pentel ain HB blackness test

As usual, I find there is little difference in darkness between HB and B. Personally I nearly always have to jump two or three lead grades to find a real difference. However I did definitely feel that Nano Dia B felt smoother when writing than did Nano Dia HB. I did not feel there was any real difference in smoothness between Ain and Nano Dia.
uni nano dia leads HB v B

OK, well now we have the final two tests. Personally I feel strength is the single most important characteristic of a thin lead, and by clicking out a short length and pressing slowly down on paper to break it, I believe the strength of these two leads is close, but there was a clear winner, and it was not Uni Nano Dia. So, I believe Pentel Ain remains the undefeated champion of strength.

Uni do claim that the Nano Dia formulation results in a low wear lead, i.e. you get to write more letters per stick of lead. So, that’s my last test. I clicked out a length of lead and drew ruled lines, as you can see. First with Nano Dia, then with Ain, repeat over and over, each time counting how many lines I could draw before the lead wore down and I hit the sleeve. Clearly this was a very subjective test as there was almost a 100% difference between the number of lines with the same brand of lead. One time I drew only 15 lines, another time 30, both with the same brand of lead. My procedure was to do the tests in pairs - I would draw a set of lines with one lead, swap pencils and draw another set with the other brand of lead. Now, here’s the thing, despite the huge variability, Uni Nano Dia never won a single match. Every pair of sets of lines was won by Pentel Ain. Sure, sometimes it was close, and sometimes it was a thrashing, but Nano Dia never won once. As subjective and imprecise as my test was I think the result was clear.

So, where does this leave me? Uni Nano Dia is clearly a good high quality lead, exactly what one would expect from a respectable Japanese brand, but I don’t think the hype matches the result and I will still be loading my mechanical pencils with Pentel Ain.

Let the controversy begin.
Togetherness, Uni Shift + Nano Dia - a beuatiful thing


Henrik said...

No controversy here Dave – I come with peace. I’m just delighted to see the Royal Danish family (or most of it anyway - Joachim, the other prince is missing) as background for something connected with diamonds. Nice going! As for the leads, nice work – not quite as mad as the unforgettable MAD’s lead tests but close.:-) Thanks.

B2-kun said...

Excellent review. I have only tried the Nano Dia HB leads that came with my Kuru Toga and Uni-Shift so far, but I think I will stick wih Ain for any future refills after reading the results of your lead tests.

Pawel Bartuzi said...

Excellent review, as usual. I must admit I also tried these new Uni leads but my tests were in no way as scientific as yours (specifically, I didnt't do any blind tests).

I used 0,3 mm 2B leads and what I tried to compare was blackness, erasability and smoothness - with blackness and smoothness being two most important factors. That's because I like the pencil to write with minimal pressure (so the lead should have good blackness or the writing will be too light) and with a feeling comparable to that of fountain pen (the lead should glide across the paper without feeling harsh or scratchy).

What I found is:

0,3 mm 2B Ain and Nano Dia are virtually indistinguishable when it comes to blackness and erasability.

The feeling of writing is different when using Ain and Nano Dia. Nano Dia lead seems to glide a little bit "above the paper" - it seems like it requires less strength to move pencil across the paper but at the same time Nano Dia is a little bit "scratchy". With Ain you can feel the paper "drag" more but the writing is smoother overall.

After several hours I decided I liked the Ain better because the smoothness is important to me. Nano Dia was however very good and if I hadn't Ain already I might use Nano Dia as well.

BTW: The first 0,3 mm 2B lead I had used was Pilot Eno but I switched to Ain as I found Eno had better blackness than Ain, but Ain was so much smoother when writing.

Shawn said...

I can't believe that you have a site dedicated to mechanical pencils. You come up second in a Google search on that phrase. I can't believe you have an article dedicated to the comparision of a new type of lead vs the reigning champion. Mostly, though, I can't believe how professional it all looks! Good job.

I don't care one whit about mechanical pencils and I read the whole article because it was so well done. It was succint and well organized. The pictures added interest or clarity and they were reasonable well done.

Hopefully other sites learn from you. Great work!

Anonymous said...

Dear Dave, where did the musical example used in your review of the Uni leads come from? I am looking for something like that exercise for some students. Thanks.

Kiwi-d said...

"Mrs Dave" has decide she wants to learn to play the piano.
Trinity Guildhall "Theory of Music Workbook", Grade 1.

Robert said...

I too have tried out the NanoDia stuff, hoping to find an ideal lead with darkness and smoothness and smear resistance. I had pretty high hopes because I've got some fabulous Mitsubishi 2mm lead that I use easily as often as I use my Hi-Uni wooden pencils.

For the most part, I agree with Dave's findings and never quite found the supposed superiority of NanoDia. I was a bit disappointed really, even though it's a good lead.

Anonymous said...

I find that the Uni Nano HB is slightly darker than Ain HB. It feels smoother when writing and wears slightly faster. I suspect Uni Nano HB is very similar to Ain B but I haven't actually used Ain B.

radellaf said...

There are now 8 brands of easily had leads for me: Pentel Ain & Ain STEIN, Pilot NeoX &Eno, Uni Nano Dia & Hi-Uni, Tombow WX, and Staedtler. That's one online supplier of Japanica to the USA. I've tried all in 2B, some in HB or 4B, and while one might be smoother or blacker, all that seems within one grade up or down (i.e., HB in one may be more like B or F in another, if you can even tell the difference of single grade steps). The most damning indictment is that if I mix up some leads refilling and want to separate my Ain Stein from my HiUni, I was reduced to the texture of the ends of the leads (Uni very flat, AinS not so uniform). Same with HB vs 2B Pentel Hi-Polymer, which was all I ever saw in the USA in 2B until I found specialty retailers or auctions. I'm sure I like 2B better for more legibility (I come from fountain pens and don't like to use much pressure), I can't for certain, even with an ohm meter or 20x loupe, be sure of which is which. 4B vs HB is pretty obvious, but I got my first 4B (polymer) leads just a week ago. No 4B 0.7 or 0.9 except in 1000kg lots from China. I'll go on with enjoying all the different brands, like I enjoy having 100+ different inks for fountain pens, but I think in all honesty it's more psychological. Maybe one day I'll do a methodical test of darkness and words-per lead. Until then, it's just fun having all the different, usually pretty, containers/tubes. I've also recently tried much cheaper store brands (Chinese usually) and found no difference enough to swear to. Only nasty surprise is how, unlike USA Pentel Hi-P leads that are roughly the same $1 per 12 in any size or grade, 0.3 is about twice the price of 0.5 in most other brands. Winner there is HiUni (GRCT Pressue Proofed High Density, whatever that means) at 20 for $5 ($0.25 _per_ delicate lead). MAYbe they're tougher than cheaper 0.3, but that size is still the only one where I sometimes snap a lead. Snapping even the cheapest 0.5 HB hasn't happened since grade school. 4B, even Ain Stein, is a little more delicate.

Kiwi-d said...

I'm surprised you don't notice much difference with the generic Chinese leads. They are clearly weaker, etc and snap much easier, being nearly unusable for me. But then you do say you press very lightly so perhaps that's the key to it. Anyway, good luck with the lead investigations and searches.

radellaf said...

The worst leads are easier to snap, I agree, but It doesn't cause me trouble. Given that, and that I find HB way too light, I assume I just use much less pressure than usual. 0.3mm is the exception, but I've never seen cheap leads just old ones (brittle Rotrings from the 1980s). The nuances of lead-feel may be less at lower pressures, too, not sure. For anyone, though, I'd suggest trying different degrees of lead and sizes before trying multiple decent quality brands. 0.4mm 2B is an interesting combination. Much hardier than 0.3, finer than 0.5. Few pencil choices, though.

Unknown said...

Thank you for this awesome comparison, I personally like Pilot Eno more than Pentel AinStein of the same hardness/ blackness, maybe Pentel's glides slightly smoother, but Pilot is much darker, and give more solid lines on paper with more grain. But for writing purpose, probably Pentel would be better and last longer than Pilot.

Togotooner said...

There is a pencil that seems to be hiding under the radar and let me assure you that after testing hundreds of pencils in search for my choice sketching tool that has the right balance of crispness, softness, and smoothness,...I have finally found it! The shock for me was that it was disguised as a RED pencil. Yes,..a Red lead pencil from UNI. The Uni NanoDia-Red (available from JetPens) is nothing shy of STUNNING. This thing lays down a line so red it would make Ferrari blush. Smooth as silk and employs the same Dia Lead that you tested here. My only thought is that there must be something different about it that is not used in the mechanical pencil leads. I would love for you to review it as well and see what you think.

Maybe its just the obvious. Maybe it's just because the core is larger and you are in fact using more lead than a micro thin mechanical pencil sized lead.

Anyway,...thanks for the review of the mechanical pencil leads and I will see if I can find this Uni NanoDia Red woodcased pencil lead in a 2mm size or .07mm.