Printing on glass

[Jeff Umsted]

Hi folks. It has been a long time since I have posted here but now I find myself in over my head and know of no where else to turn but the expertise of this forum. Please help!

My questions are regarding a glass job. The job requires a digital print for the background on glass panels. The idea is to print the background image on clear vinyl in reverse and apply it to the back of the glass, hopefully achieving a transparent look but still achieving somewhat vibrant colors, hopefully achieving the look of transparent vinyl (nice sold transparent colors only using a print instead). The background is to detailed for my airbrush skills and it has to many overprints to it that need to show through way to much for reverse painting.

What would be the best printing method for this effect? Thermal or will an ink jet print accomplish the same results. Another gentleman offered the idea of printing directly on the glass with UV curable inks and a flatbed printer but I know squat about this process and how long it would hold up.

The glass panels will be mounted indoors and I believe be out of direct sunlight, I still would like to have longevity as far as fading is concerned.

We'll start with this for now and if you have a picture of a similar job could you please post it so I could get an idea of this effect?

Thanks much
Jeff

[erik winkler]

Hello Jeff,

Mike would say that these questions are better done on the letterville forum, but since you are in need of an answer.

There are a lot of things to consider when doing printing on glass.

1) Transparant vinyl is never transparant.
I have searched and searched with all brands, but never found a vinyl that in close up did not show the orange skin textured glue layer. One of mine resellers is working on a complete transparant polyester film with a coating, because that is needed to hold the ink.

2) Keep in mind what the overall color of the interior is, since the print will not have a perfect whiteblank underlayer.
So the best would be white painted walls and a lot of highly difused lights.
The thing you do not want is a dark colored interior with just to few lights. This will be the same as to print on a black paper through your little desktop printer. When this is the situation read point 5)

3) Ink.
There is no best ink for this... but the thing you want is pigmented ink with solvents or just with UV curable properties.
The main thing is that the ink has a miimum of 3 years light-quaranty and does not scracht away with your fingernail after 1 hour after printing.

4) If you want to apply it on the inside, always remember to print the transparant vinyl in a mirror image and applicate it with white vinyl (with a white glue, not the gray one).

5) There are some special window vinyls which have the nice looking through properties, but still have the tendencies that you can print a good image on them.
A) Perforated vinyl, which has about 50% wholes which you can look through and the other 50% on which the print can clearly been seen.
B) Horizontally or vertically cut vinyl. Which has about the same 50% of the vinyl cut away in stripes on which you can look through and the other 50% on where you can print on.
C) Said this you can just print on white vinyl (maybe laminate it) and than cut the 1mm lines your self.
You can make this program using your cutting software by making one 1mm thick circle, stretch this circle to more than two inches of the hight of the window.
Repeat this newly created long oval for about the width of the window with a space of 1mm also.
After this group all the lines and make one block on the top and one block on the bottom and combine these shapes as one.
When you put your print in the plotter, measured the right force to cut and pre-spaced the exact place where you want to start cutting.
Aftercutting, start peeling where the big block is on the top or the bottom and you will be left with a nice window sticker made of a lot of 1mm lines. The only thing you will need to now is stick application tape on the whole project and cut the top and bottom of the sticker so that it exactly corrseponds the hight of your window.
This will be applied on the outside of the window.

Hope this helps.

[Jeff Umsted]

Thank you Erik. Your answer does help a lot. I was going to post this over at letterville but for some strange reason I can not get past the log in page. Have you ever printed directly on the glass using a flatbed with UV pigmented ink? This seems to be the option that I am leaning towards but am having difficulties finding a local printer perhaps because it is Sun.

Thanks again For the good info Erik

Jeff

[Danny Baronian]

Jeff,

do a search under recent posts by Roderick, and and one by Dave Smith, one on a restoration project, the other was in one of the sign magazines, a restaurant.The restaurant was an edge print I believe.

I don't know what type of images Dave ended up doing, but I believe the bird prints for the restoration were digital prints. Either that or he had considered digital prints at some point.

Look at some of the personal projects or meet projects posted here. Many of the images of recent work are digital prints from standard desk top printers. You just need to be creative in your design and create a window in which to place the print if you can.

Don't know about longevity and the best inks, but solvent based inks are what my printer uses and they've held up well. When you order the prints specify optically clear film and print with a transposed image. Optically clear film is more expensive, but as the name implies, it is optically clear.

Depending on your subject matter and use, images can be printed on either the edge or ink jet onto white vinyl with the image transposed on the print for glass.

Danny

[erik winkler]

Flatbed printing with UV inks only holds when it has been baked in a kiln. Otherwise even the prints with UV inks made on a flatbed are scratched of very easily with your fingernail.
BAKING IT IN THE KILN IS THE ESSENTIAL THING.

Printing on an edge printer may be fine, but remember that glass will magnify every ugly spot and especialy the double lines when the edge print is not width enough; and you build your window up from different stripes of 15 inches.

Dave made prints on white paper and glued them on the reverse site using a clear glue, here too the size of the image was limited and the background was white.

[Jeff Umsted]

So you think it is best to go with the digital print and possibly laminate it too?

[erik winkler]

What is best is the look the client wants.
What I like best is printing in reverse with solvent ink on a transparant vinyl and laminate that with a white vinyl with a white glue (not the grey one...).
And I like this the best, because it is the best to see from a distance.

If the client wants transparant, do not laminate it with white, but with an other transparant layer of vinyl.
But only if the overal color/light on the rear side of the window is white.

[Jeff Umsted]

SOLD!! I can't thank you enough Erik, you have been a great help with this and I now feel like I can give them what they want and also the durability too.

Jeff

[Rob Schramm]

the answer is simple call a digital printing shop, I work with one as I do murals on canvas in my business and a good friend has a roland 64" solvent printer. Here is a pic of a mural that we printed about 2 weeks ago for a job. The images are unbelievable and if your image needs to be blown up with more DPI just email it to me as I have Fractal software and can take a picture taken on a 8mp camera and blow it up to 4'w x 6't. I just converted one for a friend of her kids to fit onto a 8't x 11'w wall while still keeping quality.

[Jeff Umsted]

I know this is not the standard on this site but it was my biggest glass job to date...

Not my design, I just recreated it on the glass.

[Jeff Umsted]

ooppss...hope this works

[Roderick Treece]

Jeff,
I do alot of those. Unless your going for multi color complicated art why would you need to have that digitally printed? It could have been done with ,

Screen printing if you had alot
paint mask painting ,great for one or two
sandblast/paint fill
vinyl lettering (which I would not do)

I would reserve digital printing for something much more complicated. When did have something digitally printed on glass it came out great. It just didn't stand up to the mirroring/cleaning process.

Roderick
www.customglasssigns.com

[Mark Summers]

There are digital printer that can print directly to the substrate
such as glass or Lexan. A Zund printer will do this and 5 year print
durability. Previously I have used Stonehouse Signs in Denver to
do this printing in reverse on Lexan. Glass should no be a problem
I don't think. After printing they print or paint a white to the
backside.

Mark

[erik winkler]

Glass is a problem.
Glass is hard and therefore the ink will not penetrate the surface.
I just saw a print done with UV curing inks and after some temperature difference due to the sun the ink cracked and peeled of of curtain spots.
After the Zund printed it, you must bake the glass in an oven, like stained glass.

Erik