Glass ink holders are the best way to store inks, especially iron gall blends. These screw top glass holders are water tight, and hold .16 oz (5 ml) of ink or gouache, and they are included.  They are the perfect size to dip calligraphy pens or small paint brushes. 
The Aromatic Red Cedar holder is hand-cut, sanded, and coated with a satin varnish. It is grown in Eastern North America, and the West Indies, and its heartwood ranges from light orangish brown to darker reddish brown, with contrasting grayish brown streaks.
The piece measures 6" x 2' x 1" high.