Printing Spot color greys, new head needed? VP300. HELP

[gnatt66]

SO here's my scenerio. Can't seem to print Roland spot greys without terrible banding unless on HQ settings. if i uncheck the spot color tick it prints a beautiful NON banded blueish gray. its only spots. other colors print beautifully.

I looked/googled/searched and checked out the various calibrations, feed etc they are all really good. no adjustment needed. tried less tension on the feed (unrolling first). OEM inks. any media. tried more heat too.

test print isnt perfect but after a cleaning it is.

 

[P Wagner]

The Roland Color System bypasses ICC-based color management, and sends a direct CMYK recipe defined in the Roland Color System to the printer. For the gray colors in the RCS system, the recipe is strictly a percentage of K, with no use of CMY. This places a lot of 'stress' on the K nozzles, as any missing or deflected nozzles will be highly evident in the output, and banding will be the result.
Your alternatives would include:

a) take measures to attempt to clear the misdirected and blocked K nozzles (cleanings, soakings, cleaning solution through the head etc) to get it back to 100 percent, or
b) Find a media profile that allows you to get a neutral gray using color management (better yet build one for yourself) or
c) run a higher pass count to try to minimize the visibility of the defect, or
d) Build a CMYK gray and turn off all color management (in VW, Color Management Preset = Density Control Only)
e) replace K head

 

[gnatt66]

The Roland Color System bypasses ICC-based color management, and sends a direct CMYK recipe defined in the Roland Color System to the printer. For the gray colors in the RCS system, the recipe is strictly a percentage of K, with no use of CMY. This places a lot of 'stress' on the K nozzles, as any missing or deflected nozzles will be highly evident in the output, and banding will be the result.
Your alternatives would include:

a) take measures to attempt to clear the misdirected and blocked K nozzles (cleanings, soakings, cleaning solution through the head etc) to get it back to 100 percent, or
b) Find a media profile that allows you to get a neutral gray using color management (better yet build one for yourself) or
c) run a higher pass count to try to minimize the visibility of the defect, or
d) Build a CMYK gray and turn off all color management (in VW, Color Management Preset = Density Control Only)
e) replace K head

thanks for the input. much appreciated. i saw via some searches that some slowed the head speed down and for the life of me i couldnt find where i could change that. then while trying a few profiles (canned) and monkeying around i finally saw the head speed setting!

here is GCVP RIPC W+PASS BUT with a 675 head speed (vs stock 760). its much less bandy! (still not ideal texture but i think a head change is the only fix for that)

 

[P Wagner]

Option C...(W-pass is a 10-pass mode)