is this moire if so what to do?

[Gilligan]

accurip at 55 lpi 22.5 degrees on 150-S mesh.

this pattern is on the screen as well but not the film.

I do think the screen was over exposed as we lost the small dots.

anyway, looking to fix this if we can.

[Frog]

Try either going to a 260 mesh, or knock your line count down to 45.
In general, to best reduce your chances of moire interference patterns between halftones and mesh, you want a mesh count of at least 4.5 times your line count.

[DannyGruninger]

Since your screen has the pattern as well as the print I'd say yes this is moire. Put it on a 230/40 s mesh and you'll be good to go. We run 43 or 47 lpi on 180 and under mesh.

[Gilligan]

So basically dots are ending up being lined up on the thread itself at this lines per inch vs mesh count?

Just seems odd... but I guess that's because I haven't had to fight it before (never really used half-tones to their "full potential" yet.

[IntegrityShirts]

55lpi on s thread 150/48 doesn't work well in my opinion.

45lpi is ok, but even at 45 you won't get super smooth halftones all the time, especially on large halftone areas.

[tonypep]

55lpi=230 mesh

[Sbrem]

I don't think 150S will quite make it for you. Like the others said, go up to at least 230, and with a fade out to nothing, 260 sounds even better.

Steve

[patfinn]

You can try to do 55 again on the 150s Murakami has certain angles that yeild no Moire on their mesh. Look on their website for them. Again don't count on it to work but they say it can be done

[Frog]

I think that experimentation with seemingly crazy mesh/line count, even with a whiz-bang product is great, but should be reserved for after basic halftones are mastered.

Gilly has no (or very little) frame of reference.
I encourage newbies to shoot for a ratio of 5:1 when possible, to further eliminate possible headaches. Heck, folks want to use higher-than-in-the-past mesh counts on solids nowadays. Halftones should be a no-brainer.
As for angles, sometimes the best laid plans of mice and men etc,
We try to stretch our mesh straight, but sometimes, even a prescribed angle on the film just isn't working. That's where the breathing room of the wider ratio differential helps save our butts.
Would mesh being cocked a half of a degree be visible?

Who out there with a hundred halftone screens under their belt has never needed to re-shoot a screen?

[Gilligan]

Frog is correct.

This is the highest count we have on hand and this is also a design just for us (not a real job).

We figured, "Why not".

Tell you what though... my guy is in love with the S mesh.  It can definitely lay down some ink even though it's a higher count.  That 150/40 throws down some ink!  My guy was getting some one hit white and not even trying!  I bid a job and my pricing sheet (excel) was glitching out so I could only see the basics of the formula and under bid it by a buck (still as high as most of you guys, maybe even higher) but I was also thinking it would be a PFP job... if we can do it in one hit then that makes up a bit of that buck, especially on the time side of things.

[3Deep]

Gilly, you could have a bad wash out as well, some people don't really take the time to wash a screen out with halftones.  After you wash a screen with halftones you can hold then up to a light and see the patterns and you can find that not all the dots washed out correct.  A lot of people wash halftones soft to keep from blowing them out, but if the screen is burn correct you should not have a problem..just my 3 cents

Darryl

[ScreenFoo]

Can you tell if the threads are more or less fully blocking the smaller dots with a loupe?  I'm surprised you got as many nice dots out as you did on that.

You gotta figure, if you fade to nothing, and you have sub-100 micron dots on a 48 micron thread, that's not going to work out quite right every time.   
Can you limit the end of the fade to 5% instead of going all the way to 0%?

[Gilligan]

I figured all the way to 0% would be fine because whatever we got is what we got.

But the pattern is all around the design at about that percentage.

The thing is that the thread is WAY smaller than the "blocked" area.  So something doesn't add up there.

I'm pretty sure I over exposed a bit... that is probably some of the problem.  We exposed at our normal Light Units which is ~25% EOM on white 156.

I'd have all this dialed in but we are still struggling with coating consistently, so until then we just kind of wing it.

[jsheridan]

The real answer is you need to test a range of tones and using a loupe to examine exposed screens to find the tones that work on your mesh counts. Once you have a tonal range, try different angles (22.5 is NOT the correct angle) and again use the loupe to find the best range.

Once you've done all this, print a test shirt and give it to your wife, next time she makes tonal art, reference the test print and create tones that will fit inside that job on the mesh count you want to use.

[Orion]

Using an anti-halo mesh, yellow or orange will alleviate some of the undercutting, but I believe you are going to need a higher mesh count.