What’s the best masking tape for watercolor?

Lists of watercolor supplies usually including “masking tape,” but what’s it for? Why do you need it? What do you do with it once you’ve got it? And what’s the best kind to get? When I was first gathering watercolor supplies, I often found myself frustrated with the vagueness on supply lists. I wanted more detail so that I could get it right the first time. Since I did not get it right the first time, let me pass my hard-won wisdom onto you!

Watercolor artists generally have two purposes for masking tape:

1. To hold down the paper so that it lies flat and doesn’t curl up when wet. This isn’t necessary when using a watercolor block, where the paper is already glued down on all sides, but it’s crucial when using loose sheets of paper – you can tape them to your desk or a clipboard. It can also be helpful on a sketchbook: taping the page you’re using down and curling the tape around the edge of the book to turn it into a makeshift block. (Kolbie Blume explains this in Day 1 of her 10-Day Painting the Wilderness Challenge.) Either way, when the page is untaped, there should then be a crisp, white border framing the entire painting – as long as the tape hasn’t leaked!

2. For masking! As the name implies, masking tape can be used as an alternative to masking fluid. It’s my preference, since masking fluid gives me a headache. Cut the tape to the shape you want, then paint over it to your heart’s content. When the paint is dry, remove the tape and you should have a crisp, white silhouette left behind in the shape of the tape. This is super useful for paintings where you need to make a wet-on-wet background that’s darker than the foreground. 

For both of these use cases, the crucial properties of good tape are:

• Doesn’t leak. Can be painted over with multiple wet washes, and doesn’t let in paint underneath the tape. Not weakened by water.
• Lifts cleanly, without damaging or tearing watercolor paper. 
• Leaves behind no sticky residue, especially if you plan on painting over the area.
• Not weakened by heat, in case you plan on drying your painting with a heat tool such as a hair dryer.
• Wide enough to effectively hold the paper down. My ideal width is about 18mm (about 3/4 inch), although yours might vary. For the purpose of masking, I like to get extremely wide tape, as wide as possible, so I can cut the biggest variety of shapes out of it. I currently mask with a roll of 3” wide masking tape. 

Here are some options I have tried.

The Best

• Holbein Soft Tape, which is the same thing as Nitto Denki P-790 Paper Masking Tape. Works very well and resists heat better than most. This is a plain white-colored tape made of crepe paper that is coated with a synthetic rubber resin. It’s very water resistant; water beads on top of it, but doesn’t tend to sink in or leak, and it lifts away cleanly.
  
• Nichiban #251 is extremely similar to Holbein Soft Tape. I can’t say that one or the other is better. They are both excellent.

The Good

• Regular old hardware store masking tape. There’s usually no specific brand name attached so these can vary, but they are usually really good, in addition to being your cheapest and most widely available option. It’s not pretty, though. 
  
• Washi tape, those super cute patterned paper tapes you find in Japanese stationery stores, tend to be extremely effective at giving crisp edges and gentle on paper as well as being cute! Again, I don’t have specific brand names since there are so many and are often sold without a specific brand name attached, so they can also vary in quality, but I’ve had good luck with tapes from Jet Pens and Kawaii Pen Store, as well as from Etsy shops like LeslieWritesItAll. One disadvantage is that these can be on the thin side. I can work with half-inch width tape, but it’s not as easy.

The Fine

• Scotch Expressions, the decorative paper tape you are most likely to be able to find in the U.S. at someplace like Target or Michaels. It’s decent, but doesn’t really work quite as well or as consistently at giving crisp edges as the Japanese tapes I’ve tried. Plus, the sampler packs usually include a variety of widths, some of which are far too thin to be useful (like 1/4″ size).
  
• Rifle Paper Co. Similar to Scotch Expressions, I find these to work fairly well although there are occasional leaks if you’re using a lot of water or a heat tool. On the plus, they are a good width – a bit over half an inch – and extremely cute.
  
• Scotch Magic Tape. That’s right, regular old transparent office tape. You know what, it works fine, and it’s really easy to find. It’s a little on the narrow side and doesn’t always come up in one piece – it has a tendency to shred when you try to pull it up – but it’s water-resistant and gives clean edges.

The Bad

• Blick Artist Tape. Just horrible. This was my first roll of tape, and it let in so much leakage! Much more if I used a hair dryer, but even without, pretty bad. (Blick Masking Tape, however, is fine. Just like hardware store making tape.)

General Tips

• Remove tape gently to avoid damaging the paper. Pull it up slowly, straight up (not at an angle), applying even tension.
• Paper quality also matters. Lighter paper or cellulose paper may be easier to damage than heavier cotton paper.
• Tape that is too strong can be pre-weakened by touching it or sticking it to your shirt a few times before pressing it to your paper.
• Heat tools can weaken glue, so make sure you re-press your tape after a pass with a heat tool. The upside is that a heat tool can help to release tape that is too strong.
• Avoid leaving the tape on the paper for too long, as it can bind more strongly over time. I try to take it off within a day or two.
• Brightly-colored tape can change your perception of color saturation, so some artists find that neutral-colored tape (e.g. beige) allows for more accurate judgements of color balance. But I think washi tape is fun.
• Some ways of working don’t require you to tape down your paper, such as working on a block.
• Many people prefer masking fluid for masking, especially for smaller areas. Cutting tiny bits out of tape is a pain. On the other hand, tape doesn’t smell.

Conclusion

Holbein Soft Tape (Nitto P-790) or Nichiban #251 are a dream if you have access to them. These are high-quality crepe paper masking tapes with a water-resistant resin and gentle low-tack adhesive. If you can’t find them, basic beige masking tape or washi tape are usually reasonable.