There was a suggestion from a Eureka user.
"Could there be a method to plug the cartrige, so ink-filled cartridges can be sealed?"
This thought actually occurred to be as well,
but to achieve this function mechanically, an additional thread must be machined along with a machined Lid.
This was more complicated than I realized.
A simple method was to use a silicone plug that will be compatible with the ultem cartridge.
and... here it is !
the black color will make ink stain less visible.
also since silicone is quite durable and chemically resistant to various ink types, this is a good solution.
now ultem cartridges can be filled with various ink colors, and safely be carried around.
* when installing / removing the silicone plug, you must rotate it to prevent sudden movement.
* A certain amount of it must be inserted to make sure it won't loosen. You will be able to feel the right amount of resistance and depth.
