so don't use it in transparent pens or pens that have an ink window. It can also corrode, so don't use with a steel nib, unless you don't mind it slowly being eaten. All that being said, ESSRI is one of my favourite inks, so I recommend...
Anyway, they come in these hard cases, like cigar cases, and they have a pen clip on them. They run from roughly 5" to 6 1/2" long by 1" wide and come in a myriad of colors. The added benefit is that you get a pair of reading glasses and you can choose whatever magnification ...