My answer would be that washi (和紙) is japanese paper. So they are paper tape. They are slightly transparent, especially for the lighter colors. They work well for layering effects and are great for papercraft, gift wrapping / packaging, SMASH Journals, casual scrapbooking, card making, art journaling, and wedding/birthday decor. They should be residue free. You can tear them by hand, since they are made of thin paper. They are removable but of course not on things like thin tissue paper (although I have done it slowly with wrapping tissue paper).
If you look up on wikipedia, it says "Washi (和紙?) is a type of paper made in Japan." and "Washi comes from wa meaning Japanese and shi meaning paper, and the term is used to describe paper made by hand in the traditional manner." Although with technology, this may not be the case. So this brings me to the reason for the post. I think some people think that any kind of paper tape or tissue tape, or even fabric tape = washi tape. However, they all have different feel to them.
The washi tape under "Japanese washi tape" section are all from Japan. They are in my opinion higher quality. The original brand that started it all was MT, from Kamoi. The manufacturer also works with larger companies and manufactures for some other highly selected brands such as Marks. They are very selective about who they work with, so those that can get them to manufacture for them are the lucky ones. There are also a couple of new manufacturers for Japanese brands and their quality have been consistent as well.
Since it became popular, there are also ones made in China. Various brands from the US and all over the world may be manufactured in China. The quality of these will depend since there are different manufacturers and likely different quality control.
From the past few years of handling washi tape, I can say that the Japanese kind were always consistent. Their quality were high and stickiness and colors were always the same. I love handling them and they don't disappoint. With the Chinese kind, I did have issues with inconsistent stickiness. Some where too sticky where there's actually residue already on the tape (if I notice this, I do not list them). Others were almost not sticky at all or very low stickiness where if I used it to package something, it falls apart pretty quickly. The colors from the Chinese kind can vary from batch to batch. I do wish that would improve. Again, it does depend on different manufacturers. I believe the ones under the American brands have better quality control and therefore better color consistency.
Writing on washi tape:
I did read a comment somewhere about writing on washi tape and that they were not able to write with a Sharpie and there's a waxy coating on the tape. True, there is a coating on the tape that does keep it semi water resistant, however, I was able to use a sharpie on it with no problem. I would just not recommend liquid type of ink pen.
Stamping on washi tape:
Since there is that protective coating, not all ink will hold on washi tape. I have read that Stazon ink pad is one that worked well, although I have not tried personally. Since Stazon also can work on surfaces like glassine, I would think that would be the case with washi tape as well.
Tissue Tape, Fabric Tape, Paper Tape: What's the difference?
Fabric tape is obvious. It is made of fabric and will obviously have a very different feel from thin paper. Even with this big difference, there are still some calling fabric tape washi tape. I believe it is just because it's decorated. I think that's incorrect and they should be called fabric tape or decorative tape.
Tissue tape can be pretty similar to washi tape and may be just a brand preference from Tim Holtz. Although I have not actually compared side by side.
Paper Tape - Some US brands now have some paper tape that do feel like washi. Other US brands have their tape labelled as paper tape and they actually can be thicker paper and therefore not really the same feel as washi tape. 7 Gypsies paper tape is for sure different in feel. It feels a bit hard and is almost like a decoupaged feel. Bella Blvd, SMASH came out with paper tape and the patterns are pretty, the feel is a bit thicker and does not feel exactly like washi. SMASH brand's tape have lower stickiness. October afternoon brand tape are like washi and the quality and consistency seem good so far.
Trendy tape is another terms used by a US brand and those do feel like washi.
Wasabi tape is another term used by few customers. This basically is just a misspelling of washi, because wasabi is the green Japanese horseradish paste you get at the Japanese restaurant when eating sushi. So I don't think they use that to make tape...yet! lol
Also..make sure to keep washi tape way from dogs. I've had more than a few customers coming back looking for the same pattern they had already purchased because their "dog ate it"!
Length of Tape:
Don't be surprised to get different length of tape. Different manufacturers/brands may make them in different lengths. MT brand is now 10m in length. Other Japanese brands can be 12m or 15m. Please do look at the description of each product page for the length as well as width. The Chinese kind usually come in 10m and a few are even 8m. The core however can make it look like a huge roll - for instances, on the Sweden designed but manufactured in China kind. They are still 10m in length even though they may look larger. So don't go by how they look as a roll, but what their actual length should be.
Start your next creative project with some washi tape !