Black ink for sim process

[sqslabs]

What black ink are you using for sim process work?  We always have a bit of trouble controlling our black, even with very low pressure, and I'm wondering if our use of our standard house black (wilflex matte black) is the greater issue.

[DannyGruninger]

Wilflex matte black works alright but I would def mix at least 15-20% halftone base in it to cut some of the pigment back...... Good sim process seps usually build a little dark color under the black so you dont need a true dark black at least from what I've learned

[sqslabs]

Wilflex matte black works alright but I would def mix at least 15-20% halftone base in it to cut some of the pigment back...... Good sim process seps usually build a little dark color under the black so you dont need a true dark black at least from what I've learned

Thanks Danny, will give that a shot.  The only solution we've come up with recently is to move the black one or two notches back in the print order, which tends to ease up the contrast and smooth the gradients a bit.  I could definitely envision a more transparent black acting in a similar way at the final print head.

Pic attached of the print from today that lead me to this post.  The one on the right is with the black last in the print order (late in the print run) and the left is with the brown printed last.  Not the best photo, but the contrast in prints is pretty apparent, as well as our control issues with black ink. 

It also just crossed my mind that we ran this job on 225's across the board since its on white shirts.  Would a 305 been better for the black?  Or the other colors?

Thanks.

[DannyGruninger]

Can you post a screen shot of your separation file with the black last in the channel order?

[sqslabs]

Sure, attached..

[jsheridan]

Wilflex matte black works alright but I would def mix at least 15-20% halftone base in it to cut some of the pigment back...... G

was gonna say the same thing 

[AntonySharples]

Yeah if using matte black, you have to base it down.  If you want a money black for process, Synergy black.  I'll see if I can dig out one of our prints that we used both on and the difference is very noticeable with matte black being way too dark...even based down.

[brandon]

Colin on here taught me many years ago black does not need to come last in sim process. Most of time in the middle. Depends on art of course. But what Colin taught me opened eyes for a lot of other print jobs. Thanks Colin!

[blue moon]

you should be using sim process ink for sim process printing. Not sure what the black is that you are using, but it sure sounds like it is not an actual simulated process ink. . .

We use Unimatch Black form Union Ink, which is part of the mixing system designed for the simulated process.

pierre

[Orion]

If you use a single angle for sim process work, try offsetting the black plate 30 degrees.

[Joe Clarke]

If we fill a 305 mesh (without knowing the thread diameter) we can deposit up to 20-microns of ink. Relatively 225 mesh (thread unknown) will allow 35-microns of ink. So your comment about using a finer mesh was a good one.

The density combined with the deposit (transparency) of the black will change a solid 1:1, a 3/4-tone about 1:2, a midtone about 1:6 and has almost zero affect on the 1/4-tones and highlights.

The reflection density of typical spot color blacks on a 305-ish mesh will range from 2.0 to 2.5. Generally we would want a transparent, process black to print in the 1.75 area. This means a generic, spot color black would allow 30% to 50% base to achieve the proper density. (50% base will drop the density approximately 0.5 units). So the 225 mesh will need significantly more base in order to simulate the shadow density of the 305 printed image.

So when we add base or use a mesh to increase the deposit, (or double stroke or use a different blade) we change shadow density significantly, mid-tones gradually and highlight density barely.

Although as noted above, highlight dots don't change much at all based on the density of the ink and or the printed deposit. Conversely both highlights and shadows are most affected by a change in the area of the dot (AKA "dot gain" or "dot loss") a by product of fluid momentum (shortness) of the ink.

Similarly when we bury the black and step on it the highlights and shadows take the worst hit with respect to dot gain. If the black ink peaks when stepped on the loss of density is roughly linear; last in the highlights, most in the shadows.

The fluid momentum of the ink (and peaking) impacts the total range in the same way (highlights and shadows the most). But short flowing bases have less affect on the image change than longer flowing shot color inks.

We can run a couple test images to allow you to modify your black to suit the general set of separations.

Meanwhile like Danny and Anthony suggested, add some base. NexGen MAGIC is super short (even at maximum stroke speeds) and will reduce both the dot gain and the peaking on your current brand of black ink. I like the generic 305 over the generic 225. With moderate GCR (lay off of the spectral highlights), the right density adjust, reduced gain & peaking, and shorter flow I would run the adjusted black printing last on a 305-ish with a 75/95/75 @ minimum angle and pressure for the image you have shown. Pick a line count, a mesh, thread and tension and I will give you adv angle set. This way you will have the greatest control over image contrast.

[tonypep]

Process black=finer particle grind. If you're a purist this usually works best

[sqslabs]

Just wanted to thank everyone for the help on this.  It's greatly appreciated.