How to tell the difference between UV & Aqueous

[eric@associatedprinting]

Does anyone know how to tell whether a printed piece has been aqueous coated or UV? The piece I have does not look super smooth but the customer doesn't know how it was printed.

[jlind]

Eric:
If it's water based, you can dissolve it away with an ammonia solution, like Windex? If it's UV, try a tape pull, see if it comes away clean from the surface. UV is more slippery, from silicones. Another thought, a ball point pen should write on an aqueous coating (same as Indigo Sapphire...) but not on UV.
John Lind
Cranberry Township, PA
724-776-4718

[UVMAN]

In my experience AQ even at a high gloss will still have a MATTE TYPE OF look. UV on the other hand should have a very nice high gloss. although there are different types of UV if the sheet came from an offset press chances are it 's AQ. and if it's a digital press chances are it can from a UV Roller type of coater Like my XTRA Cure UV Coater.
please fill free to call for more help.

[bearwithme]

Not to throw a wrench in the works but...
We print UV litho on plastic. You can certainly get matte uv coating, writeable uv coating, and gloss uv coating. The writing test may not work if it has writeable uv coating on it.

[tmason]

Try smelling it. UV has a distinct odor.

[arfamoe]

Use a regular felt tip marker (not a sharpie) and draw a line on the coating, if the coating is UV the felt ink will 'Bead' and not stick, if its waterbase the line will stick to the coating.

[Freeman A.Gain]

I will agree with bearwithme! The writing test no longer applies 100%. Now, having said that, it is definately one test you can do. Not all UV coatings are writeable, and more often than not, those are special uses. So if a jiffy or pen cannot write on it, then it is UV. Smell test is also good, if you know what you should smell! Typically, UV gloss coating will be very shiny!

[Cedarman]

Folks,

I'm new here so excuse mistakes or indiscretions. I need your expertise.

My company makes household products out of aromatic eastern red cedar wood (hangers, blocks, balls, sachets, etc.).

The relevant point is that we always apply a UV coating to our packaging in the area where the wood will touch the printed cards (e.g, blister cards). Otherwise the natural oils in the wood will cause the underlying inks to bleed all over and ruin the package and product.

We have done this for years and never have problems.

Recently a large customer of ours (nationwide retail chain) required us to use a non-U.S. printer for some blister cards. The cards looked okay, UV coated area was appropriately glossy.

However, after packaging product we have found that the "UV coated" area under the cedar wood became very wrinkled and 'orange peel' looking. The ink has not bled so far, just the orange peel effect.

Does anyone have any idea why this might have happened? We have never had anything like this in the past.

Is there a simple test I can perform on the supposed UV coated area that will tell me if this is a true UV coating?

I tried the felt tip test and it does bead up on the UV surface. Also tried ball point pen and it wrote on the UV surface.

Are there different types of UV coating that might account for this?

Any help/suggestions would be greatly appreciated.

Thanks in advance

[Cornishpastythighs]

I would imagine there are hundreds of UV coatings of different levels of quality out in the market place. The felt marker test is a good cheap basic test that has its exceptions, some UV coatings are classed as foil stampable/imprintable these coatings have certain ingredients removed to allow the foil to stick to the coating and can be wrote on. If I read this correct, you used to apply the UV coating yourself or at least had some form of control over the process, now you have no control and have no idea of the quality or application process of the problem coating. Time to visit your 'new' supplier if they are not 10K miles away and put in some quality specifications, Its your reputation hanging on the shelves mate.

[Vee]

Time to visit your 'new' supplier if they are not 10K miles away and put in some quality specifications, Its your reputation hanging on the shelves mate.

Well said. Even if they are 10k miles away, you need to check them out; and clearly communicate your expectations.