Pentel Pocket Brush–Art Supply Test & Review

This will be my first product test and review! I would like to immediately point out that I have not been paid to do this in any manner. If I ever am paid to do these posts, I will make it very clear at the top of the review that it is a sponsored review. I don’t expect this to be a thing, ever, but it’s important to me that anyone reading this knows that this is an independent, fully personal review.

Image source:

As the title would suggest, today I’m going to dick around with be showcasing the Pentel Pocket brush. The two models sitting on my desk here are specifically the GFKP, it comes in many colours and patterns. I have the solid black one, and the other is a special edition for a Japanese dating sim that I’ve never played and couldn’t tell you the name of because I’m too lazy to look it up. It was a gift and it’s cute as hell, so I have it.

Pictured: Joy incarnate.

The packaging can vary depending on where you get yours. Not a lot of people I’ve met seem to know this, but Pentel is actually a Japanese company, and as such, some of their products have more than one model number depending on where it was meant to be sold. You might find the Pentel Pocket Brush in different packaging under the model number XGFKP. Rest assured, the only difference is the packaging. I know this because I’ve handled both models before, and they are identical. I let someone borrow my XGFKP and I never saw it again, unfortunately, so I don’t have it to compare. No hate, though. These are pretty great brush pens, so I don’t blame them.

Let’s inspect the body, because that’s not a weird thing to say about anything. The pen measures approximately 5.5 inches (14cm) long and a hair under a quarter of an inch (.5cm) wide. It’s a plastic barrel with a metal clip on the cap, and the cap fits snugly with a satisfying little snap onto the pen. It also sits firmly on the rear of the pen during use if you want to store it that way. I like to jam the cap in my mouth while heavy breathing over my projects like the disgusting cretin that I am. Also the bristles are made of nylon.

Speaking of ink, the barrel unscrews, and inside is where the replaceable cartridges go. That’s right! These pens are refillable. This appeals to me because I actually get pretty bummed out just throwing away spent pens, because that’s a lot of waste over time. The hollow barrel is also long enough to accommodate a refillable cartridge adapter, if you want to use your own inks. I use both Platinum Carbon Ink and Pentel’s FP10, the latter of which is made for this pen specifically. I can compare these inks in a later review. Today we’re testing the stock FP10 that comes with the pen.

Pictured: “Don’t look, I’m naked.
Pictured: Squid bullets.

In terms of fineness, the Pentel Pocket Brush is considered to be a “medium” tip. There are similar products in the Pentel brush pen line that are finer tips, and there are thicker ones. The medium is a really good choice to just have on hand, because the nylon bristles actually come to a delightfully fine point. Those of us who are experienced with inking with a brush can make very fine lines with it (razor thin consistency is hard, though), and those who are just getting started will be pleased with how forgiving the tip really is. This is an excellent choice for an all-purpose carry inking tool.

On With The Testing!

For reference, I am demonstrating on Bee brand cold press 100% cotton watercolour paper (rough surface). This is a surface that can be unforgiving, but many sketchbooks people will be using this pen in gave papers with a decent amount of tooth to them. That’s why I picked it.

The Eraser Test

For this test I used, from left to right, a standard General’s Kneaded Eraser, a Sakura Foam Eraser, and a precision pencil-style eraser manufactured by Faber-Castell that has a similar texture to the rough Pink Pearl erasers, but is white. I wrote the sentence in 2H lead, then scribbled, then inked it, then erased parts. There was virtually no lifting or fading of the ink under the pressure of the kneaded eraser or the foam eraser. There is very light fading from the rough eraser.

Pictured: Shrapnel.


As far as waterproofing, here it is under some water applied with a watercolour brush after being left to dry for about three minutes.


Nib Hardiness

As I mentioned, this pen has nylon bristles. And they will take a beating and come back for more. Unlike natural hair bristles, if you smash the crap out of these against your paper–for whatever reason, I’m not here to judge–they will go back to a nice, dainty point when they resaturate with ink. Have a look at the beating these will take. I literally smashed it into the paper with a nice, healthy THUD every time for this shot. Came right back to a point.

Pictured: Unnecessary violence. WHAP WHAP WHAP.
Pictured: “IS THAT ALL YOU GOT?!”

Line Thickness

The line thickness test is garbage because I’m doing it on rough paper and I’m feeling much too lazy to do it on something smoother. *COUGH* I mean, I want you to see how fine of lines you can actually get on heavily textured paper and I totally did it like this on purpose with a lot of forethought. Yeah. That one. As you can see, you can get some pretty fine lines out of this, even on rough paper. It’s worth noting that I did the line thickness test AFTER I did the smashing of the nib. It’s pictured here with a .5 mechanical pencil for scale.

Pictured: “Who’s line is it anyway?”


This is just a texture/value test. One of the benefits of using heavily textured paper is that if you change your brush pose around a bit, you can manipulate the distribution of the ink flow onto the paper. Here is a messy gradient.

Pictured: Birth of a Photoshop grunge brush.

Image Drawing

Here’s a fish I drew. Let’s name him…Fork. Fork says “Noot Noot.” Fork is only about three inches long in real life, and I sketched him in ink in about five minutes. This was to show off the pen’s actual drawing capabilities in this environment. Also I like goldfish. Say hi to everyone, Fork.

Pictured: What am I doing with my life?


So now you’re all the way down here, and if you’ve made it this far into my whimsical fuckery, then I’d like to thank you for hanging out this long. I hope this has been somewhat helpful for you. Here are some at a glance details for anyone who went crosseyed reading this:

-Lightweight, easy to hold for hours
-Can technically be vegan
-Can choose your own ink
-Hardy bristles that can make fine and broad strokes
-Pen does not have leaking problems in bags
-Comes in many colours
-Inexpensive at between $15 and $20 USD

-Brush pens take some time to master
-Medium brush head cannot consistently deliver perfect fine lines
-Brush nib is not replaceable, so if it is damaged the pen must be replaced
-If you loan this pen to anyone, you might not get it back

Where to buy:
Most local craft stores actually do carry this item. I’ve also seen it on Amazon,, and

Questions? Comments? Something else you want me to review? Leave me a comment!

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