







🎨 Master every fine line with precision and style — your secret weapon for flawless art!
The LOONENG Ruling Pen is a professional-grade, cross-hinged technical pen crafted from durable stainless steel and plastic. Designed for fine line drawing, calligraphy, and cartography, it features an adjustable screw wheel to control line width from ultra-fine to thicker strokes. Compatible with masking fluid, Indian ink, gouache, and drawing inks, it offers smooth, drip-free application and easy cleaning. Its enhanced fluid reservoir allows longer drawing sessions without frequent dipping, making it an essential tool for artists seeking precision and efficiency.










| ASIN | B0CCPLTQ85 |
| Age Range (Description) | Adult |
| Age Range Description | Adult |
| Best Sellers Rank | #13,052 in Arts, Crafts & Sewing ( See Top 100 in Arts, Crafts & Sewing ) #154 in Drawing Pens |
| Body Shape | Round |
| Brand | LOONENG |
| Brand Name | LOONENG |
| Closure Type | Snap |
| Color | Black |
| Customer Reviews | 4.5 out of 5 stars 2,224 Reviews |
| Drill Point | Fine |
| Grip Type | Plastic |
| Hand Orientation | Ambidextrous |
| Ink Base | Water |
| Ink Color | Black |
| Item Dimensions | 5.9 x 0.3 x 0.45 inches |
| Item Height | 0.45 inches |
| Line Size | 0_3mm |
| Manufacturer | LOONENG |
| Model Name | RP23A002 |
| Model Number | RP23A002 |
| Point Type | Fine |
| Style | Cross Hinged |
| Unit Count | 1.0 Count |
| Warranty Description | None. |
| Writing Instrument Form | Technical Pen |
S**M
Works perfectly with both masking fluid and paint, cleans easily
I used this both with masking fluid to mask some light reflections on cold-press watercolor paper that needed to be regular lines. Just dipped it in bottle, keeping masking fluid well below hinge piece and the screw wheel. Practiced a second to get the angle right for a nice line on a scrap piece. Once you get the angle, it flows smoothly, and the weight is nice and feels balanced in your hand. Lines are clean and smooth, and the tool holds way more fluid than I had expected. No trouble with drips, and the wheel is great for adjusting the width of line as well as for clean up. For clean up, I used just a barely damp paper towel (damp from wiping my brush after painting and dip rinsing in clear water), and you couldn't even tell it had been used. Tried it out with some watercolor paint from a palette well to smooth a line in places, and it worked like a dream. Again, just dipped, gently and quickly stroked outside once against clean edge of palette well. No drips, no need to put in with a brush, at least for me. Clean up still fast and easy no residue. Excellent product.
K**S
It works better than anything I've used to apply resist for watercolor!
What I love: 1. It goes on smoothly 2. It adjusts between very fine lines for hair to thicker lines. 3. It cleans up completely and saves fine brushes. 4. The reservoir makes it possible to draw several fine lines before needing to dip again. This makes it quick so you can put the cap on in less time, therefore preventing the resist drying out. 5. I have only used this with Pebeo resist. I can't say it works as well using other products, because I haven't tied it with any other brands of resist. I am one happy girl! This reduced tons of frustration!
K**T
Works just as I hoped
I bought this product for creating fine lines with masking fluid. It works really well, just as I hoped - when fully closed it makes very fine lines, when fully open it makes thicker lines. Both are consistent and smooth. It was easy to use and clean. Just dip it in a tiny container filled with masking fluid or the bottle if the opening is wide enough and go - I didn't even have to wipe off the excess from the outside. The only thing that's a little tricky is that the opening in the tip has to be parallel to the line, so turning corners/making sharp turns accurately can be difficult, but that's just how ruling pens work - I just need to practice.
S**E
Lost the screw nutfirst time I used it
I only got to use this one time and it worked great! Had not used anything like this for 55 years since I was in drafting class in high school. However, I only used it for masking fluid one time and when I was cleaning it, the little gold screw nut came off. I threaded it back on and put the pen back in the package it came in. When I went to use it the next day, the little gold nut was gone. I've searched for it and looked for a substitute in my vast collection of nuts and bolts and screws, etc. No luck.
K**H
Cool tool
Why did you pick this product vs others?: There are so many different ways to apply masking fluid. I like to paint in watercolor and I already had a bottle of fluid and using brushes is awkward, so I thought I would give this a try. There’s a little bit of a learning curve but it’s a neat tool. There is a little screw on the side where you can adjust the space that holds the fluid. Having fun with it so far and I don’t need to worry about it clogging.
I**N
High quality, well-made ruling pen
High quality, well-made ruling pen. Excellent for using with liquid frisket to preserve whites in watercolor paintings.
B**Y
I use it for watercolor.
It does the job for me, but isn’t the best quality. I wish it made a really , really thin line, but the price was right.
P**L
Great for use with masking fluid in watercolor art
Works great with ink but I use it first masking fluid in my watercolor art.
Trustpilot
1 month ago
1 month ago