Just got this from HLJ, Tamiya Masking Tape Refill (6mm) and Tamiya Masking Tape Refill (10mm). The reason I've been wanting to get this for the longest time is because most model maker reviews I've read recommend to use this type of masking tape for painting.
The Tamiya modelers masking tape adheres real well to the plastic surface, but more importantly it is soft enough to contour easily to a model's odd & extreme surface edges to prevent gaps from forming that will allow paint to seep right in. This will result in crisp lines when painting. Of course, even with the use of Tamiya masking tape, it doesn't mean you have a license to over paint/over spray as this will really lead to paint seepage. Another adverse effect of over spraying is that when you pull out the masking tape it could lead to tearing of the paint at the masking tape lines.
Each roll of masking tape has 18m worth of available tape, which should last very long, unless you are a heavy user. Then I'd recommend that you get more than one roll when you order *snicker*
The plastic pouch of the masking tape isn't resealable, so I'd recommend having a cool dry place to store this in so that the temperature and humidity won't ruin the glue part of the masking tape which will prevent it from doing its job of effecting a good seal.
There's also variants of the Tamiya Masking tape being sold by Tamiya that come with a free dispenser (ex. 6mm, 10mm). The widths available aren't limited to just 6 & 10mm as there are other widths of Tamiya Masking Tape Available.
Tried out the 10mm Tamiya masking tape to make some stripes on a base I was working on and I have to say that the reviews were indeed true, this product is really impressive.
Compared to ordinary masking tape, the tamiya masking tape creates crisp & straight lines. No problem also when peeling off the tape, it didn't rip off the primer below. Considering too that the primer was just put on about an hour ago.
Looks like basing on this I can conclude that the Tamiya Masking tape has just the right formula of adhesive to allow it to stick on the surface of the model to allow it to be taken off without peeling the paint underneath while allowing a perfect seal to prevent paint from seeping in.