Funnel with OPEN-CLOSE Mechanism
You can use this funnel with powder-like substances like salt, sugar, fine (dry) sand, (poppy-)seeds, pigment, glass frit, ...
or with thick fluid products like honey, cream, glue, paint, ...
It was NOT designed to provide a 'water-tight' solution, but give it a try, you never know...
Print parts 1, 2 and 3.
Use a hexagonal pencil (I used Bic / Conté Evolution HB no.2 pencils)
Put the cap on top of the pencil (part 3 that is)
Put the pencil through the hex opening of part 2
Assemble the parts using a rubber band
You will need to cut about 10 mm. off from the top of the pencil, or sharpen the pencil... 8)
Once the resulting setup is satisfactory, you may put a drop of glue inside the pencil cap.
Two small M2x6 bolts may be added but are not really necessary.
Print SLOW (better quality)
On the Flashforge Dreamer : Base print speed 20 mm/s, first layer : 10 mm/s, 75-100 % infill.
UPDATE : made version 2 of part 2 : The thumb-end is now thinner, resulting in more 'reach' at the pencil-end.