Bad mottling

[Maxie]

I have a job set up on a automatic that is very mottled in a solid area printed with M3 Yellow through a 225 Screen, has a White base.
I have exposed a 305 screen that I will try and use tomorrow, thought of also increasing off contact.
Any ideas on how to get rid of this will be welcome.

[Colin]

First thing I would check on is to make sure the base white is not being over flashed.  Second, check the print speed and pressure of the yellow.  You may want to slow the print stroke and maybe increase the pressure.

Is the yellow ink up at print temp?  Typically around 80-90 degrees F.

[livinthedream]

Could also help if you could post a picture of what you are seeing, might help narrow down the speculation on what is happening.

[mk162]

is that a 225s?  I would drop it to either a standard 230 or 280.  The 305 should work fine as well.

I have found those 225s dump down a good amount of ink.  Too much for WOW on a base.

[Maxie]

Here are two photographs, one close up before I did the adjustments Colin suggested.
These helped a lot but I'd still like to see a smoother yellow and whiter white.
All screens are 225 except for a brown over the yellow which is 305.
I normally print this kind of graphics with 225 base and 305 for the rest, I thought 225 for all would give me a brighter white.
Seps by Dan.

[blue moon]

to me it looks like you need more off contact (based on the second picture and yellow ink having the pattern of ridges in it).
white brightness might be related to the garment (assuming you have everything else dialed in correctly). Try using a roller to flatten the underbase. It will help, but ultimately, you might need two hits of white to make it work.

pierre

[Colin]

Looking at your base white:  You do have quite a few fibers coming up.  What shirt are you printing on? 

Pierre's suggestion of the smoothing screen will help immensely.  Followed by controlling your flash times/temps so your base white is not "to dry".

Now, yellow ink.... never a fun one when you are battling texture (fuzzy shirts) or opacity issues. 

You may very well want a second white screen to give it the pop you want, or try what Pierre suggested.

[Maxie]

We use shirts from India that are great, I dont think its the shirt.
I'm not sure we used the roller, will check but the white base is a 225, are you suggesting PFP using two 225 screens?
Would you put the roller after first or second white?   Or print/flash/roller/second white

[Colin]

If the shirts are really good, I would revisit your flash times then.  If the ink is coming out - not tacky, but "moist" feeling, while still being dry - then you have hit the right time/temp.  The ink is still pliable and really responsive at that point.  Thats when you want to hit it with a roller screen.  What squeegee hardness are you using in your base white?  Pressure/speed?

If you find that the print is still to weak/fuzzy then run 2 print strokes for your underbase.  Hit it with the roller and see if its improved enough for a good looking final print.

If you feel that there are still to many shirt fibers coming up or the yellow does not pop the way you want, throw in a second base white screen.  For this screen I would pull back on the tonal range a bit so you dont get any more dot gain.  Use the roller after the first screen followed by the second base white.  Here, I would use 2 - 225s mesh screens.

Test Test Test.

[Dottonedan]

Ah,  Now, I see the picture.  Nice printing on the machine.  Good advice from above.

[Maxie]

Here are the improved prints.
Used a 50/90/50 on the base white and double stoke(225)
Cut back on flash time.
Double stroke on Top white to get the lettering on top whiter.
Used a lighter grey.
All screens 225 except for brown which is 305.
There are two photographs
One has the brown printed before the yellow and the other the brown after the yellow.
I think the customer will prefer before the yellow, the machine is supposed to be yellow.
Thanks for all the advice, learned a lot.

[blue moon]

That looks nice!

Pierre

[tonypep]

Correct on the color, lemon yellow is Karcher

[Colin]

Lookin GOOD!