Have never seen this happen.................

[Gino]

Some background.

We just finished a partial wrap today. The customer was over earlier and said he just loved it. The colors were perfect and the copy and pictures turned out great. He later left and we finished post heating a few spots. Everything still looked good. I just took it out front of the shop and when I got out to look at it..... all the greys were green.... and I mean green. I took some pictures, went back inside and the leftovers still looked completely grey. HUH ?? So, I took Jeremy out and then Larry. We had all kinds of reasons, but then I took some of the leftovers [which were still completely grey] out and when I reached the front door, the light [bear in mind, it is an overcast day and no bright light showing] they instantly tuned green. Went back in and they turned grey again. I've never seen this. It's 3M 180 with cast laminate. Everything is done according to specs in that department. We have fluorescents and incandescent inside and it all looks the same in here. I could post up a picture, but even the pictures, they look the exact grey they're supposed to be. I've never experienced this. Any ideas ??

thanks.............. Gino


here ya go anyway........... it just doesn't look green here
​

 

[Gino]

Well, even the perf did it, too...... and that isn't 3M, but has the exact same hue of green outside and the correct grey inside. I just hope he picks it up after dark and tomorrow I'll tell him something must've landed on it overnight..... like a beam from a spaceship. Yeah, that's the ticket, frickin' Martians got a hold of it and tampered with it.

 

[JBusch260]

Just out of curiousity, did you use a different profile, or did anything change with your color profiles?

 

[Gino]

Nope.

 

[JBusch260]

Hmm.. a similar thing had happened to us. We use a couple different profiles for stuff, but for vehicle wraps it never changes. We ended up with the green as well, luckily the customer liked it (?!) and wanted us to keep using that. So we did, fingers crossed that accident kept happening. It did. I almost think it might just be the shade of gray issues that Pat mentioned. Some just don't translate well once natural light hits it.

Is it a gray that you use regularly?

 

[laserman70]

Had similar issue.
Grays can be such a pain in the a$$.
Ours looked great in shop, outside looked greenish as well..

 

[300mphGraphics]

http://en.wikipedia.org/wiki/Metamerism_(color)

 

[jmcnicoll]

Curious, what's the make up of the grey color? If in the file it's just black your rip must be printing it with a 4C mix. If you can get it to use more black in the make up of the color, the shift from light source to light source should be less.

jim

 

[danno]

I have seen it happen. We usually crop a test print out and check both inside and outside to make sure the greys don't turn green. Sometimes it is a profile mismatch causing the problem, sometimes we will need to rebuild the gradient. The lighting in your shop is probably like mine and will not match the natural light.

 

[Gino]

We have mostly fluorescents, mixed in with some incandescent, but we looked at it out back in the truck bay areas early on and we have lotsa natural light coming in from the open garage doors. I can see or understand a greyish tint going to a warm grey or a slight tinge of green to it, but this went like from PMS 443 to PMS 5545. I can't figure it out, but here's the kicker.

The guy just left a few minutes ago and when he came in, I told him I had some not so gooda news. He looked like a deer in headlights. I took him out to the truck and showed him the color shift and he said.... I like it better than the original. He said really, this is the effect I wanted, but my graphics guy said to go straight grey. So, he couldn't say enough until I told him it cost more to change to this color and then he said, let's settle up before I can't afford this thing.

So, we dodged it this time, but I'm gonna always take these tests outside instead of just near the open door and make sure I'm seeing things right.

Thanks to everyone who contributed good ideas. If there are any more out there, feel free to post up and we'll try to prevent others from this kinda mess in the future.

:U Rock:​

Gino
​

 

[P Wagner]

This is actually a fairly common occurrence, particularly with grays. This happens for several reasons:

1) Human vision is very good at discriminating differences in near neutral colors like grays.

2) Grays are typically built using all four colors in process printing (CMYK), and not only K ink. The amount of light that reflects off of these various components in the gray versus the amount that is absorbed will vary as the color temperature temperature of illuminant changes. As noted previously in this thread, this is referred to as a metameric failure. All of this is useful information as to the source of the problem, but the question remains: What to do to minimize or possibly eliminate it?

3) The solution is to use more K ink and correspondingly less CMY in the grays. This is a function in the ICC Profile called GCR (Gray Component Replacement). More aggressive use of K in the ICC will mitigate or even eliminate this metameric failure from happening in the future.

 

[TheSnowman]

I myself have had the green/grey curse from time to time. Don't notice it as much now with my new JV33, but on the old JV3 it was non stop.

 

[thesignexpert]

We ran into this some years ago with neutral grays, beiges and even straight blacks. It was particularly bad with the JV3 SSII inks. We did some tweaking to the color profiles and made sure to always double check our colors out in natural sunlight (where the final wrap will be seen).

Now we run HP latex printers and Mimaki JV33 will no gray issues at all. We still stick to the habit of checking our colors in natural sunlight though.

 

[SignManiac]

Just happened to me with same material. Grey indoors and greenish tint outside on a jump plane. I'm freakin out of my mind.

 

[Santimus]

that happens all the time to me. I have to go outside to color check. I usually wind up having to add more magenta to the color which makes it look like a pinkish gray indoors but when its outside it looks perfect. It's just a pain in the a$$ to have to let the HP L25500 warm up and do its thing before it actually sends out a color sample for me to take outside every time I need a new gray. You have to do what you have to do though. If your product will be outdoors, match to a daylight setting til something else is figured out.

 

[Jester1167]

Greys are a pain in the ... to hit and grey fades are even worse and indoor versus outdoor just makes it that much harder. Now add 3M's laminate that has a slight yellow cast and things get even worse.

When I was printing we had a policy that we printed color proofs on the material and laminate used for the finished product and the customers proofed it in the environment where it would be viewed (indoors vs. outdoors). We quickly got tired of admiring our work as we were installing and being disappointed when we pulled it outside. The color shift can be dramatic.

 

[Seano32]

I have had this problem before. Always with my solvent printers. Rolands. Mimaki. But Hp prints silver/grays perfect. I always proof my colors outside never under interior lights. I have also tweaked my colors in the rip by backing off the yellow ink saturation a bit. The yellowish tint of the 8518 lam will bring this hue back up and not make it look as green. I have also had my silver/grays have a reddish or blueish hue also. Golds are the same for me. Looks great inside and greenish outside.

 

[ddubia]

We've changed all our lamps to full spectrum. It helps somewhat but outside is the real thing and grays still look different but as bad.

 

[SignProPlus-Chip]

A true gray should not be a problem to achieve. I know light is an issue here, but are you printing with the gray color in the file being just a percentage of black? Using a percentage of a full CMYK rich black or RGB will cause shifting to green, blue, purple etc...

Your print profile can also be "color correcting" a straight up percentage of "K" to a mix of CMYK too.

 

[inthesignbiz]

When in doubt, I will make a reduced print - 10-25%.
Take it outside and inspect for the evil green - purple.

 

[Gino]

Yeah, I guess the general consensus will be from here on is, to print a small sample and go outside to be sure.

It's just that this is the first it has ever happened to us in this way. We've had profiles or certain medias or what have you print wrong from the gitgo, but never from a perfect color match inside, until you get the finished product outside..... with or without laminate. I mean outside, it looked completely green. No hint that it might've been grey.

I hear what a lota ya are saying about the human eye can only distinguish a certain amount of colors, but how does that equate to the actual photo also seeing it wrong ?? In the photo I posted, it looks fine. Only in person... outside does it appear wrong. Ei, ei, ei.... but this is stoopid.

Anyway, other than greys..... are there other colors from which one has to be careful ??
​

 

[HulkSmash]

common issue. the UV in the wrap lam does that.


we avoid it by de-saturate the grey in Photoshop to assure there's only black in there.