Lower Opacity On Pantones?

[raerae]

I had a client show me a sample package design that was two colors; black and a spot color. There were two squares of color; one was the solid pantone and one looks lighter but when you look close it's a halftone pattern. My question is this; to create the lighter colored square, did the designer intentionally create that halftone pattern or does a spot color print in that pattern automatically if the opacity is lowered?

[Kool]

I wouldn't use opacity, use a screen percentage instead. Rips will read it fine. All kinds of weird things can happen with opacity.

[SpugNothuson]

A tint of the spot colour was more than likely used. Make sure you use tint and not opacity though.

When a tint goes through the RIP it will be asigned a screen angle and lines per inch value.

The screen angle determines what direction the halftone pattern appears to flow in.

The lpi (lines per inch) is how many dots you will see (unless stochastic/AM screening has been used but thats a different and fairly uncommon kettle of fish)

The tint value will change the size of the halftone dot.

e.g. A 50% tint at 0 degree screen angle would create a checkerboard effect sitting perfectly horizontal on the sheet. (0 degree is usually used for yellow)

A 10% dot at 45 degree angle would create the same amount of dots as the checkerboard but they would be smaller circles and appear to be running from one corner of the sheet to the other.

Does all that make sense? Have I answered what you asked or just waffled on at a tangent?

[raerae]

Totally making sense, thank you so much. I don't really have any experience using spot colors. So, if the client gave me a sample, there's no way for me to assume what angle degree was assigned and what the tint value was? Well actually I just re-read what you wrote... I wouldn't assign the angle, the printer would, right? However, I would need to assign the tint in my file...?

[SpugNothuson]

Yep you would asign the tint value. The printer would usually do the rest. You could stipulate what angle you want the Spot Colour to come out at but you'd be getting into territory that needs a lot of research and understanding. Its better their fault it goes wrong than yours. Could be the difference between you footing the bill for the reprint or them. :eek:

Do you have a magnifying glass to look at the halftone dot with? The way I decide what the tint strength should be if all I have is some previously printed material is to guestimate the value of the dot when scrutinised.

Look at peices of work that you know have a 10% dot, 20% dot, 30% and so on. Look at the dot sizes. Get a feel for the way it works. It's not always as simple as 25% must be equal spacing between black dots and white spaces, the screen angles can play tricks with your mind (optical illusions). After a while you'll get it down to within a couple of percent of where you should be.

In the mean time let the client know that if you're to be working to a previously printed piece of material that they need to expect slight colour shift and tint variations. This is not always an exact science we're working with.

[raerae]

Perfect; thanks Spug!

[milano.design]

I lost you... what would happen if you chose 70 % opacity in the program vs. using the 70% tint of color?

I have to say i've been playing around too much with the indesign opacity feature. And so far have only used it for overlay of color on a photo, but i did notice it looked a bit muddy for my tastes. Client liked it, but, wonder now if there was something else i should have done to make the colors crisp... I just figured it was a dirty press...

[SpugNothuson]

Opacity and Tints as you've no doubt noticed may appear to give the same result but are actually two quite different beasts.

A 70% tint on a white background and a 70% opacity on a white background will look and print the same.

Throw an image or another colour into the background and now you'll see the difference. The tint will knockout the background image/colour whereas the opacity block will, for want of a better word, overprint it.

It is by no means the same as overprinting, I use this term to put this point across only.

For a basic diagram see below;
http://i3.tinypic.com/4v47lh0.jpg

[urstwile]

Perfect example, Spug. :)

[milano.design]

thanks. knew that part. curious if those two colors were SPOT. would it work out the same way.

or spot over cmyk...

or heck... it was the part you said about staying away from opacity that can create all sorts of problems that you had lost me in translation.

The screen angle determines what direction the halftone pattern appears to flow in.

The lpi (lines per inch) is how many dots you will see (unless stochastic/AM screening has been used but thats a different and fairly uncommon kettle of fish)

The tint value will change the size of the halftone dot.

e.g. A 50% tint at 0 degree screen angle would create a checkerboard effect sitting perfectly horizontal on the sheet. (0 degree is usually used for yellow)

A 10% dot at 45 degree angle would create the same amount of dots as the checkerboard but they would be smaller circles and appear to be running from one corner of the sheet to the other.

what would happen in above instance, if it wasn't a tint but opacity?

I could just be confusing the issue.

[SpugNothuson]

If it was a Pantone overlapping the yellow box you would still see the yellow box underneath it.

Using transparency in a document can cause issues with some printers. If you save the document as a PDF over version 1.4 (Acrobat 5 upwards) then the transparency will be retained inside the coding of the PDF. The printers RIP will need to flatten this out to run the job accurately.

When a RIP flattens something the behaviour of how it does this is dependant on the style of RIP and when the RIP was made. Some do not support transparency at all. If you KNOW that your printer can accept transparencies and you're confident that it will behave itself then you'll have no problem.

If however they do not support transparency then you will need to create a PDF 1.4 this version does not support tranparency and the document fill be in a flattened state when created. Check out your newly created PDF to make sure that it looks as you would expect. It will then print as you would hope it to.

If you don't need to use transparancy effects then it is best not to. Do not substitute an Opacity effect where a simple Tint will do the job.

A 70% opacity is basically saying take this 100% colour but let 30% of whatever is behind it to show through, if it's a white background then 30% white will show through and a 70% tint is achieved.

Whereas a 70% tint is saying this colour is 70%.


As you can see the tint version requires less interpretation.

[morea]

well done, Spug!

[Broacher]

I've had good success using transparency in spot work in AI. And not to be overlooked is the very powerful opacity mask feature. If you save to AI and place in ID it seems to work too! The overprint preview is very helpful when working with this kind of work.

[urstwile]

Excellent explanation, Spug. :)

[sierng]

I agree. Great explanation!

What happens if you have to use transparency? And want to preserve the effect?

Does saving it as an eps, then saving the eps as a pdf work? I did that with some guys work at uni, and it seemed to save the transparency effects. But I'm not sure if there would be issues when coming to printing.

[SpugNothuson]

I'm guestimating on this one, someone will either confirm or disprove me in a couple of posts. Here we go...

An eps is esentially a postscript file. Postscript doesn't support transparency effects. It contains the data that is required to be interpreted by a printer (harware printer, not the ageing alcoholic grumpy kind). An eps stands for encapsulated postscript, put simply it can be slapped into another document for layout purposes. When the eps is printed it will go through the postscript system again but the original postscript code in the placed eps will be retained in the new postcript code from the layout.

Phew!

To answer your question a little simpler. An eps is postscript info and does not support transparency, therefore making a pdf from an eps will be create a flattened state pdf.

[seamas]

I hope I am not going off subject, but I have always desired, when using 2 color (spot and black) to be able to mix those colorsto get a broader range of tone and color.
(I usually work in Quark & Illy, sometimes Indy).
Is my only way to do that by means of a duotone eps?

Or is there a simple means (overprint?) to do that right in the layout program?

[Broacher]

You can make Mixed Inks Swatches and even auto-generate Mixed Ink Groups in ID (access this through the top of the Swatch palette). Something like (maybe even better) in Quark. Not sure about AI.

[seamas]

You can make Mixed Inks Swatches and even auto-generate Mixed Ink Groups in ID (access this through the top of the Swatch palette). Something like (maybe even better) in Quark. Not sure about AI.


Geez. I just tried it out (Quark). So damned easy, and SO much better. I've never noticed that functionality -always desired it (for richer 2 color pieces), but have never seen it in any of the literature I've seen. (I am now kicking myself for not knowing this all these years).

I'm looking forward to my next 2-color job.

[PrintDriver]

I wonder if your printer is. :D

[hewligan]

If you can't make the occasional printer weep into his ink, what's the point in being a designer? :D

[seamas]

I wonder if your printer is. :D

Is that right? It'll drive 'em crazy?

I wouldn't wanna do that. I'd just love to have that range of color with using just 2 spots.