LOONENG Ruling Pen for Masking Fluid, Perfect Fine Line Drawing, Technical Cartography and Calligraphy, Suitable Use with Drawing Ink, Indian Ink Gouache

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.

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!

I love how you can control bleed proof white paint to cover watercolor spots that leaked from under masking tape. It’s also good for applying drawing gum to detailed areas. You can adjust it to your needs. Great design art tool!

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.

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.

High quality, well-made ruling pen. Excellent for using with liquid frisket to preserve whites in watercolor paintings.

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.

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.