What nozzle size should I use for filament containing glitter? I recently had a series of issues with my prusa MK3 that kicked off when I tried to print with Proto-pasta's glitter filament using a 0.4 mm nozzle. The glitter clogged up and cleaning it out was pretty difficult.
A different user here pointed out that 0.4 mm was too small for glitter filament. When I initially read (and, after the clogging fiasco, re-read) the Proto-pasta website I didn't find any information suggesting that a larger nozzle borehole diameter was necessary.
I have the glitter and metalic green filaments. Do I need a nozzle with a larger diameter to print these or not? I emailed Proto-pasta about it the other day but have yet to hear back.
Update
Here's the reply I got from proto-pasta on these questions:

Thank you for following up. Yes cold pulls that leave behind material can cause all sorts of trouble. It happens to me on the Lulzbot quite often, probably my biggest gripe about that machine.  Anyways, on to your questions:

Is this accurate? Should I print the glitter filament with a nozzle with a larger borehole diameter?
A larger bore is not needed, the glitter flake is quite small and flows through a 0.4 nozzle fine. However, using a 0.4 nozzle and printing layer heights of 0.1 or 0.05 with glitter can cause a shift in apparent color as it forces the glitter to lay down flat.

If so, what diameter should I use? 0.6?
While not needed, a 0.6 nozzle does allow for a better sparkle or shine from the glitter filament.

Are there other proto-pasta filaments that require a larger borehole?
Generally any metal or wood filled filament benefits from a large nozzle size. For example, wood filaments most people suggest a 0.5 for better flow but they do work at 0.4. For us, we like to use 0.6 on the metal fills as it allows for a good flow.

I have a spool of matte fiber htpla that I got with my last order. Can I print this with my nozzle?
The matte fiber was designed as a non-abasive alternative to the Carbon Fiber filament. It does not require a larger nozzle, a 0.4 will work just fine.
Fact is that you encounter clogs with this filament, so trying a larger diameter nozzle is an option to solve this. Nozzles are very cheaply found in various sizes, so buy a few and experiment. Commonly found larger nozzle sizes are 0.5, 0.6 and 0.8 mm nozzles, even larger nozzles exist, like e.g. 1.0 mm or even larger, but keep in mind that the hot end needs to keep up heating of the extruded filament, so deposition speed may need to be reduced for larger nozzle diameters.

Alternatively, you could fight clogs the usual way by playing with temperature, layer height, retract settings, oiling filament, purging nozzle from previous filament or cooked up residue, etc, etc.

Quoting someone's experience:


  As far as differences, here has been my experience:
  
  
  0.5 mm low back pressure (High speed), and very hard to clog,
  0.4 mm medium back pressure, rarely clogs,
  0.35 mm high back pressure and very easy to clog.
  




Edit: According to Proto-pasta, concerning filament with glitter, a 0.4 mm nozzle should not be a problem as the glitter particles are smaller, the print layer thickness definitely can be a problem. However, they state that a larger diameter nozzle will result in more sparkle as the glitter is not laid too flat.