Idea for better metallic inks for printing (bigger flakes)

I have never printed metallics before in letterpress printing and would love as much feedback as possible to this question and your views. Metallics are alot glittery on screen printing because they use bigger metallic particles. On letterpress they are smaller and do not have as much of a shine or glitter. So my question is if I bought metallic silver flakes that are normally mixed into clear silkscreen Ink and instead took those silver flakes and put them into letterpress ink what would happen? Would it not print good? And if not then why? Would it destroy the rollers?

I think the metallic flakes in letter press inks are no bigger then 25um and in silk screen they are 100um. But if letter press ink is packed with silver flakes normally used in silkscreen why would it not roll on as normal with letter press plates????

Anyone with experience with what I am asking????

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Also there is 30um, 50um, and even 70um flakes as well as 100um flakes that are used in silk screening. So if someone knows why 100um flakes wouldn’t work then what about something smaller but still bigger then the conventional size around 25um which is not very shiny?

Hi Star-

I see what you’re saying. I hope I can help you, maybe in a way to understand a couple of things if you do not already know them; I do work with metallics in screen printing and have done it with letterpress as well a fair amount, as well.

Largely, the lack of luster you’re seeing in your metallics may be caused by more than just the size of the pigment particles; the root of the problem could be a combination of things.

There are three things that could be contributing to a dull metallic application:
1. Stock/substrate category. (Matt finish, uncoated stocks usually have a matt finish to the ink, right? regardless of oil or rubber based, they absorb the vehicle and even the pigment particles sort of stick into the substrate a little under a microscope view- you’ll see paper particles coming up through the ink.)

2. Amount of ink transferring/tack of ink.

3. Lustre of the vehicle VS pigment density (this also affects #1 to a great degree.)

So, since we letterpress people are already trying to print on nice, matt finish cottony absorbent papers, and using oil based metallic inks that are designed for offset, we are usually kind of already taking part in 1, 2, and 3. To get a good transfer of ink that is clear, a lot of people under-ink and might even need 2-3 passes of either ink or impressions to get the color up full. When you’re talking about metallic ink that is already “underdressed”, with regard to pigment load, well- you’re looking at a problem there.

In simple terms, what I am going to try to say is that when printing on uncoated, matt finish, absorbent stocks- letterpress does transfer a hefty amount of ink; but the oily vehicle which would NORMALLY coat the metallic particles gets absorbed into the paper a bit, the pigment particles also get impacted into the paper a bit, and you wind up with less luster than if you see the stuff on glass or on rollers, wet. So, what you ‘see’ is not what you ‘proof’.

If you apply the same ink to coated, glossy stock with minimal impression, (that is, a stock which is not as absorbent), you get a very shiny surface.

If you do this with larger particles, you’ll get similar results. It may have a more sparkly, uneven/glittery finish, but you’ll also have other issues which come up. Particles that are larger work sort of like sandpaper. They’re rougher. They’re more abrasive to the rubber rollers, and more abrasive to the ink train in general; when I screen print with larger particles, we actually see screens break down sooner than when we work with the fine stuff. (I have tried the full range of SIPI and other metallics that Nazdar Source one offers, for example, as well as some other manufacturers of metallic pigments.)


So, now here’s my advice: Try “Underpinning”.

Print a layer of metallic, let it dry on the sheets. Then, without changing the plate position, the guide position, or even removing the base/chase/etc from the press, run the sheets back through for a second pass. See how much shinier the result is.
Try a third pass.

Sometimes it just takes more work to garner the results you expect, and this will also increase your losses- you will probably need a lot more overage/make-ready, and you’ll need to be able to feed really reliably (dead on, actually).

Good luck!

Another way to tackle Metallic ink printing in Letterpress is to print a base layer down first. For Silver ink we use to print a light blue base first and for Gold a layer of yellow works quite well.
good luck.

We don’t have good enough register to do a double pass, one pass is the best we can get.

So let me ask some things and thanks for your help by the way:

If we mixed silk screen silver particals in with the ink (these are bigger) will that wreck the rollers because the partial size is bigger then normal metallics? Is that what your saying? How many impressions until you think it can do damage to the rollers if any?

And if we apply a varnish once or twice to the paper first is that considered a coated stock for metallics?

So your saying we can print bigger silver particals but it could rub off or you just have some feel to it? I am a bit lost in what you were saying for some of these questions. Because we were hoping with bigger particles to get more of a metallic sparkle which you cannot get in the current partial size that comes in metallics for letter press. So we thought about mixing silver particles used in silk screening in with clear gloss letterpress ink. Hoping to get more of a sparkle (glitter). Wondering if it would work or if our rollers would get wrecked. If it would stick to paper we varnish first or rub off.

Also we are printing words not doing halftones and are printing on regular bond paper. But laying down a coat of varnish first.What we are hoping to get is a bit of sparkle which you cannot get from the current metallic partial sizes offered in letterpress ink. So with a bigger partical size mixed with gloss we hope we can get a sparkle but not sure if it will print or wreck the rollers. Or even work for that matter.

I would say you should give it a try if you think it may give the results you wish. You certainly could not damage the equipment or rollers with a test application; it would take long use to wear the rollers. You don’t indicate what type of press you are using, but I assume it is not an automatic press or you would be able to achieve the close register on a second run.

Give it a try and see if it works.

I have run metallic inks without any noticeable deterioration on the rollers. Short runs only, thorough clean ups. You mention you are using a varnish? I have been wanting to try printing an overprint clear varnish and then overprinting it with a metallic ink to see the results.

How are you going to apply the varnish?

This whole post is not anything about regular metallic inks. Its about adding bigger flake particles to the ink. Instead is using small 20um flakes normally in ink we would use bigger silver particles used in silk screening and put them in letterpress varnish. I want to keep it only about this topic. Not regular metallic ink. So back to the original questions with using the big silver particles of what I was asking above? The ink will be used in a letter press. Same as offset press but with a flexo plate or polymer plate. There is a ink atrain obviously. Will the big particles not carry over? Will they not glitter from being bigger? Will they wreck the rollers from being bigger? Will they flake off the paper? Why are people using fi e grinded flakes instead of big ones that would make more sparkle? There must be a reason?

Hoping “Haven Press” can still respond to the follow up questions. And thanks by the way since you sound experienced in what I am asking?

If I hear you correctly, you want inks that glitter or sparkle.

Much of the time in letterpress or offset, the silver colored flakes are designed to be “leafing,” which means they will lay flat to have a mirror-like look as much as possible. This is NOT a glitter or sparkle. Here is an example of a silver pigment (which is almost always aluminum, by the way):

Note that the particles are up to 45 microns (I was surprised that they are that big).

If you want inks to glitter or sparkle, you will probably, (as you have said), need to use flakes which are bigger, and get them to land at different angles and dry that way. That could be a tough job unless you could print the flakes in a UV varnish, which would cure instantly and “freeze” the flakes at the different angles, before they had a chance to settle down flat and “leaf.”

Probably the only way you are going to know if any of this works is to try it.

Starm, you should try it and report back.

I corrected and edited my post above, to try and make it a little more clear.

Thanks Geoffrey. Sadly I am unable to try this anytime soon as I am away from the press. But I was hoping some sort of feedback as to why the flake sizes are always so small in letterpress/offset printing. Because there are advantages of having bigger flake sizes to me for sparkle and companies also always like to sell different options. So the only suspect for people not doing it to me is that there must be something wrong with it to make it not work. And I am trying to figure that out and see if anyone knows why. Because if it did work I assume people would be doing it? I assume you would also get a better metallic look with bigger flakes then small flakes in gloss letterpress varnish. People always complain that the metallics are not shiny or glittery enough in letterpress or offset printing so I figure bigger flakes would solve the problem so there must be a reason people can’t use bigger flakes then or I assume they would turn to them. I have read the size cant be bigger then 25um to work in an offset preas. But I figure thats because of the watter unit and letterpress has no water unit.

I think that smaller pigment particles are preferred (and specified) because they go through the press inking system better and print better. Ink companies use what they call a “NPIRI Grind Gauge” to check the pigment particle sizes in production batches of ink. NPIRI stands for National Printing Ink Research Institute. Here is more information on grind gauges:

As you look at this information, look for the parts which are labeled NPIRI.

Grind gauges are blocks of steel with one or two beveled channels milled into them. For ink, at one end of the block the channel is .001 inch (25 microns) deep, and the channel gets shallower and shallower as it goes along, until the depth is 0 at the other end of the block. They put ink in the channel, and then draw a smooth piece of steel over the channel, which functions like a blade. They start drawing the “blade” over the channel at the deeper end. As the channel gets shallower, any larger pigment particles reach a point where they get caught by the steel “blade”, because they can no longer get under the “blade,” so they are dragged along. These larger particles then make a scratch mark in the ink, which is visible.

As I recall, the usual specification for most inks (not metallics) is 3 scratches at the 3 mark on the gauge. Since each mark on the gauge is 2.5 microns, the 3 position is 7.5 microns deep. So that means the ink sample can have no more than 3 particles which are 7.5 microns in size, and no particles bigger than that.

I explained all that to show you that the ink industry places high importance on small particle size.

I agree with you that if the ink industry could have made an ink with bigger metallic particles which glittered, and also printed well on a press, they would have done it. They put a lot of time and effort into research.

That link does not work? Can you check it? Thanks.

So I guess this means bigger flakes won’t make it through the roller train which is why it won’t work.

I can imagine that after time large metallic particles would abrade rollers in an ink train in a printing press-try printing metallic then dusting over again with the particles(hand bronzing)-or even continue just silkscreening with them?

In making model railway landscapes there are special ways of dealing with fibres to get them to stand up to represent long grass-might be worth checking out.

Starm, that’s strange because the link works for me.

However, another way to get it would be to Google: Gardco Fineness of Grind Gauges. That works for me as well.

In relation to ink, there is a factor used by commercial ink and printing companies called “printability,” which is how well an ink performs on press to print. Ink can have poor printability for a variety of reasons. Maybe it doesn’t transfer well in the roller train, or maybe it prints with a mottled appearance, or maybe it piles (builds up) on the rollers, etc., etc., etc. Sometimes the cause is hard to pin down because inappropriate resins or other ingredients were used by the ink maker, or for other reasons. If you want to see poor printability, try putting some latex paint on your press in place of ink (no don’t, it’s a mess) and you will see the worst in printability.

So anyway, using bigger flakes could push the ink into the category of having poor printability.

Grinding Ink, I have a 3 Roller Mill and grind. also I check my grinds with a Grind gauge, just as an example, we used to have a Company here in LA which made inks, Kramer Ink, I got a hold of a couple cans and a student used it, it’s a brilliant ink, a bit lose, so I put it on the gauge and it even register, it’s so coarse ground.
Back in the days of Trade trained Letterpress, we would print with a clear varnish and than apply gold leaf to the printed varnish, it sticks, another run thru the press with just type, and than clean up, that’s how we got sparkling type.
Foiling is flat! is not in business anymore.

Does anyone know of a company that sells matellic ink or matellic flakes your allowed to mix in the ink that sparkle a bit at least? Like glitter? Because regular metallic inks shines but do not sparkle or glitter due to the flakes being so fine I think?

By the way I do want to thanks those who have put their time in leaving feedback to help. Of course I want to hear as much as possible but for those already who posted thank you so much because it has been helpful.