Backlits, How are you doing them?

[sballinger]

We are looking at samples from CET and Oce and noticed the 2 layer (color/white) on plexi is not producing a quality backlit. You almost have to go the route of the 3 layer (color/white/color) to get it right. We currently print our backlits off the LX850 on the HP backlit film and using opti-clear to mount on milk plexi.


Are others with flatbeds printing the 3 layer or doing a different techinque?

 

[Gino]

When we have to, we'll print directly to the face with two hits.

Preferably, we like to reverse back-print to clear with a double hit and back up with a separate white face.

There is the two step process of..... like the old duratrans, where you can print to two separate pieces and when putting them together, they look fantastic, but it's harder for us to align that way.

 

[Craig Sjoquist]

Translucent vinyl hand cut only

 

[miker]

Color white color is the way to go for prints. Seems that a single hit of white from most flatbeds isn't adequate on clear material.

 

[Bly]

HP Latex.
Sure they look a bit dark unlit but light up nice with the right profile.

 

[SeaWriter]

Let's get a debate going..........
The correct technique is to sandwich white between two layers of color.
Yes the printing of color/white/color (on a clear) is the easiest. However the white typically does not have enough body to reflex light during the day and yet remain translucent enough at night, so people end up printing on white translucent substrate, effectively being white/color/white/color. The ideal technique is to print reverse color on the back , flip it over and print on the front of white translucent. Way to much trouble and chance for misalignment.
What may seem like more work and cost, but produces spectacular color when back lite is; print on the front of your standard white translucent substrate. Print a reverse image on clear self adhesive, on a light table, apply to the back. In most cases registration does not have to be perfect, in fact the print does even have to be full saturation.
Sounds complicated, but the finished lighted result is in a different league.
Trivial note; the actual process of sandwiching white between two layers of color for the purpose of backlighting is actually patented, so we are always breaking the rules.

 

[401Graphics]

Print double hit on clear vinyl, laminate, and apply to translucent white polycarb.

 

[chafro]

Do you need to mount them?

Most lightboxes have two plexis so you just put the backlight in between them.

I print tons in latex backlight and duratrans and rarely mount them. Only for very specific needs.

By the way try the drytac Mediatac adhesive it's clear enought for clear mounting and costs 1/5 of most optical clear adhesives.

 

[Mosh]

Most lightboxes have two plexis so you just put the backlight in between them

What world do you live in? We use Trans vinyl on POLYCARB never plexiCRAP, if it need a full color print we print it on our roland using trans white film. You are WAY over thinking this simple job!

 

[Z SIGNS]

We print on trans white then apply the print to white polycarb then print on the laminate and apply that over the print.

 

[fresh]

Let's get a debate going..........
The correct technique is to sandwich white between two layers of color.
Yes the printing of color/white/color (on a clear) is the easiest. However the white typically does not have enough body to reflex light during the day and yet remain translucent enough at night, so people end up printing on white translucent substrate, effectively being white/color/white/color. The ideal technique is to print reverse color on the back , flip it over and print on the front of white translucent. Way to much trouble and chance for misalignment.
What may seem like more work and cost, but produces spectacular color when back lite is; print on the front of your standard white translucent substrate. Print a reverse image on clear self adhesive, on a light table, apply to the back. In most cases registration does not have to be perfect, in fact the print does even have to be full saturation.
Sounds complicated, but the finished lighted result is in a different league.
Trivial note; the actual process of sandwiching white between two layers of color for the purpose of backlighting is actually patented, so we are always breaking the rules.

For those of us not going after national accounts, or those of us who only replace faces, not install entire new lightboxes, this is a very, very expensive solution.

For argument's sake, lets say you charge $X/sq ft for one layer of printed, laminated translucent vinyl applied to 3/8" polycarb. How much more would it be for you to produce the face as described above? 1.5X? 2X?

I ask because perhaps the added cost to fabricate the faces in this manner is insignificant in comparison to the rest of an entire new light box. But when someone calls us to replace faces on an existing box, they are usually taken back by the first price I give, I think they might just faint if I tell them its going to be twice that to have it look slightly better at night.

For all the big accounts you may work on, there are many more smaller shops that need signs, too. Sometimes it doesn't make sense to invests thousands in making their lightbox look the best it can.

edit: Also, this is for those of us without a flatbed printer / can't print directly on the substrate.

 

[iprint]

I guess I don't understand the reasoning for your question. On our Oce, color/white/color second surface on clear is the way to go and they look outstanding lit or not. Sure you use a little more ink, but I would think that if you are pricing your backlits appropriately this should be a non-issue. I have also printed first surface on milk plexi with just color in "quality density" mode which looks great as well when lit. Not so great when not lit tho and no protection from scratching.

 

[WYLDGFI]

We have the ability to run 3 ways in our shop depending on the client's needs
Double hit on our solvent is easiest to do...but least flexible as far as the color goes. We have the ability to lay slightly different density of ink in this case though and still looks great for certain applications. Darker during day but quite nice when lit.
Our HP Latex gives us much better color overall on dense prints for backlit. Deeper black and richer color...again still darker during the day but choice of 150% or 250% hits.
Our QS with White allows us to print multiple images in-line. We rip a 130% denser image for the bottom portion then tell the printer to white flood it. The final top image is the color correct one. The white ink isnt opaque or block out the majority of the underneath image but it does give enough hide during the day. The translucency at night is excellent.

 

[JoeBoomer]

When I was at last sign shop we would:

Print on Oracal 3640 w/ "high density" (basically just an overprint). Then laminate and apply it to the face of polycarbonate (or acrylic).

Although I feel like this is a bit of a cheap way out, (using calandered vinyl) it worked great and helped keep the cost down. And we had backlit signs in the field for 5+ years.

 

[sballinger]

I like the answers I'm hearing. The reason for the question is because we would like to move away from mounting prints to substrate (sintra, plexi, etc) and just print to the material. We are an in house graphics dept for a exhibit house and we have the lightboxes made in house so printing to plexi would be more cost effective. I do like the color/white/color but i know it will cut down the production speed quite a bit

 

[JoeBoomer]

Backlit film

I started using Magic Backlit Film (SBL-7 Polyester Backlit Film) on my L26500. Very pleased with the results. It is white translucent so it diffuses the light pretty well.

Here are a few prints that are just taped to the windows in my shop.

 

[BOP]

Kevin BOP

I started using Magic Backlit Film (SBL-7 Polyester Backlit Film) on my L26500. Very pleased with the results. It is white translucent so it diffuses the light pretty well.

Here are a few prints that are just taped to the windows in my shop.

I have a Roland and use Versaworks for my software. Do you double print these?

 

[sfr table hockey]

Just a tidbit on SLB7.

I tested some on outdoor backlits. They look great in the day and night and can be printed on waterbased or solvent printers but need to be laminated and the edges sealed with the laminate. Using a clear mounting adheasive you can adhear it to the lexan.

If you use indoors they don't need to be laminated but if touched or bumped they can be scratched or soiled easily. So best is to laminate and protect. Also hinging works indoors as opposed to using a full coverage of an adheasive mount.

If you use outdoor and there is a chance they can get wet, even with the face laminated the edge of the media tends to wick up the moisture and you will see the wet area as it wicks and changes the color in that area. If you can cover the edges with the laminate and wrap a bit onto the back this should stop the wicking issue as it seals the edges. Don't poke the laminate to release bubbles as that can also create a spot to absorb moisture.

SLB7 may not be the first choice for an outdoor backlit but can work and is a bit easier to get great color with only one print layer and not need to double print.

 

[synergy_jim]

color / white / color on the CET. Printed on the back face... beautiful results!

 

[adrock]

We've got a Roland XC-540, and I currently do backlits with either 2 passes on translucent white media, or printing on clear, applying a layer of white translucent over the clear in the laminator and printing a second layer.

We've been looking at getting a 3rd printer (also have a CAT-UV), and have been considering the XR-640 or a Mimaki with white ink capabilities. Does anyone have any advice on whether a color/white/color process is viable with machines like these?