TSB

screen printing => Separations => Topic started by: Mark @ Hurricane Printing on July 13, 2015, 03:11:30 PM

Title: underbase : how many point stroke?
Post by: Mark @ Hurricane Printing on July 13, 2015, 03:11:30 PM

I have a simple two color job requiring an underbase....I currently have the underbase at a 1 point stroke..is that enough? should it be more?

I am using coreldraw x5

printing on a manual

Title: Re: underbase : how many point stroke?
Post by: zanegun08 on July 13, 2015, 03:30:20 PM

Not sure if it is the same for Corel Draw as illustrator, but I do .5 - .75 if using a dedicated base, and 1pt if print flash printing a base, and doing colors on top.

Keep in mind that this is a centered stroke so the actual choke (trap, bleed) is half that value.  If I were to stroke to the inside, I would do half the amount.

Title: Re: underbase : how many point stroke?
Post by: Mark @ Hurricane Printing on July 13, 2015, 04:15:04 PM

thanks..i am going to go with a 1 point stroke, which gives me .5 inside..

and only one color going on top...i am not going to stroke the highlight white areas.

Title: Re: underbase : how many point stroke?
Post by: mk162 on July 13, 2015, 04:34:23 PM

I use .5 here.  used to use .25, but honestly jobs set up faster with a thicker choke.

Title: Re: underbase : how many point stroke?
Post by: AntonySharples on July 13, 2015, 07:09:25 PM

I took Pierre's advice and started adding a .5 pt trap to top colors instead of choking when I can.  It is very helpful for thin lines where choking the underbase loses the thin lines.

Title: Re: underbase : how many point stroke?
Post by: Rockers on July 13, 2015, 07:43:23 PM

We choke the underbase by  around 0.28 mm - 0.3 mm. Sometimes trapping the top colors is the better option though. I`d say it`s a case by case basis.

Title: Re: underbase : how many point stroke?
Post by: Colin on July 13, 2015, 08:57:20 PM

Depending on thickness/thinness of lines int he design - all trap/choking is done as a .5 stroke.  Yes, the inside trap is .25 points.

White plates are printed through a 150(S) mesh for 95% of all jobs.

If the base will be done on the manual as a print flash print then the trapping will be .65-.7 points.

Title: Re: underbase : how many point stroke?
Post by: jvanick on July 13, 2015, 09:22:19 PM

wow, we must be gluttons for punishment here... we choke at .3pt on the line.  so .15pt.

generally jobs are setup within a few micros... I'm going to shoot some screens tomorrow with a .5 and see if Tiffany notices the difference on the print.  If she doesn't I'll bet we can get away with almost never touching the micros at all..

In fact this will be fun... I'm not going to say anything, and see what she says late in the day about how printing went.

Title: Re: underbase : how many point stroke?
Post by: ScreenFoo on July 13, 2015, 10:28:28 PM

Pshh.  Sep 'em butt-fit.  What's wrong with your screens?  ;)

OK, just kidding.  Half point on the manual here.  Less or none on the auto, depending on art.

Title: Re: underbase : how many point stroke?
Post by: jvanick on July 13, 2015, 10:31:43 PM

Quote from: ScreenFoo on July 13, 2015, 10:28:28 PM

Less or none on the auto, depending on art.

personally i don't like seeing the underbase when looking at the print from an angle..

Title: Re: underbase : how many point stroke?
Post by: ScreenFoo on July 14, 2015, 12:03:17 AM

I end up choking underbases a hair with the exposure unit if everything is just run butt-fit, so I'm cheating a bit.

I don't like seeing a little white from the side, but I can't say I like the look of a quarter or half a point of ink choking in tiny negative details either.
And yes, it keeps me up at night.