These are fine tipped pens that seem to glide across the paper surface with ease. They do not bleed out quite like the Rotring or the Tombow marker pens but definitely nice to work with. I like for sketching with an added dimension of the wash but still maintaining that "sketched" look with pen and ink.
This set includes the wrap and I like that there's an added zipper compartment there to the left as you view the screen. I can stick my little waterbrush in that compartment; grab a small sketchbook; and off I go.
Here are a couple quick sketches playing with a few of the colors along with a color chart for all the pens in this set.
Left done in Moleskine Watercolor book
and right side in the Handbook Sketching book.
One of the advantages to these pens is the fact they are fine-lined and water based/soluble for wash but will "set" first application of water brushed over the lines. After that, you can use watercolor and brush to add color if you wish without worrying too much about ink bleeding and contaminating the watercolor wash like I've found with the Tombow pens. Of course if one doesn't "set" the ink first and goes in with brush and watercolor, the results will not be the same and probably disappointing.
With that said and in defense to using the Tombow pens (which I absolutely love), it seems the ink does set to some degree but maybe because it's a thicker application, not all the ink is set with an initial water brushing. That possibly leaving unset ink to bleed in with the watercolor when it's applied. I'll have to do some more experimenting and playing ........ comparing the two type of pens ......... but so far this is what I've concluded on a quick trial.