These ink storage units come in a package of 5 stackable slots to make 1 unit. They allow you to store your ink pads and to the side you can store your markers.
They can be found on page 125 of the annual catalog. Or if you visit my my store you can find them. The item number is #149168 and they are $14.00 for a package of 5.
They are sackable so how ever you store your inks they can be an answer. I absolutely love mine.