Anyone got suggestions as to how to get clean lettering on the back of a glass or plastic panel? I want clear letters on a black background so they can be backlit by LEDs or bulbs, not black letters on a clear panel (which would be the easier route). I see stuff like this everywhere, but don't know how it's done.
Yes, I could call a sign-maker's shop, but it's Friday night and they won't be open again until Monday. Surely someone here will know how it's done and I can scratch my curiosity's itch sooner.
Grey
Yes, I could call a sign-maker's shop, but it's Friday night and they won't be open again until Monday. Surely someone here will know how it's done and I can scratch my curiosity's itch sooner.
Grey
Educated guess:
Screen printing.
http://www.reuels.com/reuels/Silk_Screen_Printing_Instructions.html
Screen printing.
http://www.reuels.com/reuels/Silk_Screen_Printing_Instructions.html
I have silk screened things in the past. I had considered it for this, but I've got a couple of observations:
--The silk screen pigment, be it ink or whatever, is either thick enough that it retains the crosshatching of the mesh it was forced through...or if it was thinned enough that it would flow under the mesh, it was also thin enough to leak under the edge of the pattern I was trying to print. For a T-shirt, poster, or the front of a drink machine, that's not a big problem. For good, clean lettering, it's disasterous.
--The link assumes that you're printing to fabric, paper, or something similarly porous. There's no mention of anything that would adhere to glass or plastic.
Grey
--The silk screen pigment, be it ink or whatever, is either thick enough that it retains the crosshatching of the mesh it was forced through...or if it was thinned enough that it would flow under the mesh, it was also thin enough to leak under the edge of the pattern I was trying to print. For a T-shirt, poster, or the front of a drink machine, that's not a big problem. For good, clean lettering, it's disasterous.
--The link assumes that you're printing to fabric, paper, or something similarly porous. There's no mention of anything that would adhere to glass or plastic.
Grey
Al,
Yeah, that's kinda my fallback position. That's the method I use for circuit boards these days, so I already have the transparencies on hand. The problem is that the toner isn't completely black. I end up running two passes each on each of two transparencies--for a total of four layers of toner--and it gets difficult to register all four layers properly.
I'm also not sure what I'd use to glue the transparency 'paper' to the glass/plastic, although I'm sure that there are any number of glues that would do the job. Perhaps something like rubber cement.
The overall registering of the print within the glass/plastic would be a cinch, however. All I'd have to do is print a period in each corner, prick it with a pin, drill matching holes in the glass/plastic, and align the whole mess with a bit of wire driven through the stack.
It's just that I'm hoping for a more elegant solution.
grimberg,
I'm not looking to frost the glass or plastic, just mask out parts. My intention is to have print something along the lines of, say, 14 point or so, probably no larger than 20 point. Not very big. It's going to be really easy to lose the clean, crisp edges on the letters. As far as I know, the etching stuff isn't capable of that level of resolution.
On the other hand, perhaps I'd be able to tempt gullible young things by inviting them to come see my etchings.
Grey
Yeah, that's kinda my fallback position. That's the method I use for circuit boards these days, so I already have the transparencies on hand. The problem is that the toner isn't completely black. I end up running two passes each on each of two transparencies--for a total of four layers of toner--and it gets difficult to register all four layers properly.
I'm also not sure what I'd use to glue the transparency 'paper' to the glass/plastic, although I'm sure that there are any number of glues that would do the job. Perhaps something like rubber cement.
The overall registering of the print within the glass/plastic would be a cinch, however. All I'd have to do is print a period in each corner, prick it with a pin, drill matching holes in the glass/plastic, and align the whole mess with a bit of wire driven through the stack.
It's just that I'm hoping for a more elegant solution.
grimberg,
I'm not looking to frost the glass or plastic, just mask out parts. My intention is to have print something along the lines of, say, 14 point or so, probably no larger than 20 point. Not very big. It's going to be really easy to lose the clean, crisp edges on the letters. As far as I know, the etching stuff isn't capable of that level of resolution.
On the other hand, perhaps I'd be able to tempt gullible young things by inviting them to come see my etchings.
Grey
GRollins said:
What size mesh were you using?
Many moons ago I had a very nice 600 mesh stainless steel screen and never experienced that kind of problem.
Got it from a large silkscreen supplier that also carried inks and screens for industrial purposes rather than just t-shirts and stuff. Expoxy inks, special resist inks for printed circuit boards, etc.
Wish I could remember their name. Did some quickie Googling and wasn't able to find them or anyone equivalent. But I think your key to success will be a good quality, very fine screen and the appropriate inks.
Ah! Here you go. Check these guys out.
CRS International
They've got the inks and very fine screens, though they don't seem to offer pre-made screens.
se
With silkscreening, it's a matter of matching ink and image to screen, but more importantly, getting the screen bias angle correct, getting the tension high enough for a good snapoff, setting off contact, and choosing the right emulsion. There's no reason that you can't use a 325 screen and dry emulsion for any reasonable lettering job.
Steve,
They have inks they say will adhere to glass and plastic. Might be an option. I wish they had it in something less than gallons, though. It's not like I'll be doing a thousand of these things.
I don't have a clue what the mesh was. It was a light, nearly transparent fabric, but that's all I can remember. This was thirty years ago or more.
SY,
I confess that I'm in conflict with myself over this. I love the way it looks, but have questions about long term reliability. I seem to recall hearing somewhere that McIntosh uses silkscreening to do their glass faceplates. They look nifty, but bubble after a while--and if McIntosh hasn't gotten it right after all these years, I'd rather do something else. Other manufacturers seem to do plastic (granted, I don't know if they're using the silkscreen process), but have not been around long enough to judge durability.
Someone with experience in plastics may pop up and say this is easy...just print such and such a film and heat-bond it to your Plexiglas. I don't know. How the devil do they do these drink machines with plastic fronts? Mass produced toys? Control panels in cars?
I'm trolling for ideas. Don't need colors, just black background with letters left clear. Preferably cheap. Don't honestly care if it's glass or plastic.
Grey
They have inks they say will adhere to glass and plastic. Might be an option. I wish they had it in something less than gallons, though. It's not like I'll be doing a thousand of these things.
I don't have a clue what the mesh was. It was a light, nearly transparent fabric, but that's all I can remember. This was thirty years ago or more.
SY,
I confess that I'm in conflict with myself over this. I love the way it looks, but have questions about long term reliability. I seem to recall hearing somewhere that McIntosh uses silkscreening to do their glass faceplates. They look nifty, but bubble after a while--and if McIntosh hasn't gotten it right after all these years, I'd rather do something else. Other manufacturers seem to do plastic (granted, I don't know if they're using the silkscreen process), but have not been around long enough to judge durability.
Someone with experience in plastics may pop up and say this is easy...just print such and such a film and heat-bond it to your Plexiglas. I don't know. How the devil do they do these drink machines with plastic fronts? Mass produced toys? Control panels in cars?
I'm trolling for ideas. Don't need colors, just black background with letters left clear. Preferably cheap. Don't honestly care if it's glass or plastic.
Grey
Found this: Screen printing inks designed for glass and plastic.
http://www.inkcups.com/dotNet/pages/2j_inks_chart.aspx
What I didn't find though, was a color laser printer that can print on just about anything flat ike thick wood wood or plastic. I saw it in a magazine recently.
http://www.inkcups.com/dotNet/pages/2j_inks_chart.aspx
What I didn't find though, was a color laser printer that can print on just about anything flat ike thick wood wood or plastic. I saw it in a magazine recently.
So I get off of work last night and I'm driving home. Look down at the dash. Scads of buttons. Black plastic with backlit nomenclature. True, the black is matte instead of gloss, and the lettering is translucent white instead of clear, but given how many places you see this sort of thing, I imagine there are several ways to accomplish the goal. It's just a question of getting an overview of each process and comparing them.
Grey
Grey
Ok, just got off the phone with my laser guy.
After telling him what you were looking to do, he sent me this photo:
For this he just took a piece of cast acrylic, used some Krylon paint that's made specifically for painting on acrylic, and then lasered a positive image on it. As you can see it also includes halftone imaging so you're not limited to straight black and white.
In this piece, where the acrylic is lasered, it's frosted. He says that extruded acrylic can be lasered leaving it virtually clear ("hardly noticeable" he says). He also says that while he hasn't tried it yet, the same technique should be able to be done on glass with the laser power turned down sufficiently that it only vaporizes the paint and doesn't frost the glass.
You say you want the lettering clear, but unless you're going to use something like an EL panel for backlighting, it seems to me that backlighting would be rather problematic without something to diffuse the light.
With the acrylic or glass frosted, you already have a means for light diffusion without having to use a separate EL panel or milk glass to provide diffusion.
If you paint the panels yourself, this could be done rather inexpensively. He doesn't charge large setup fees and pretty much just charges for machine time.
If you'd like to explore this option, let me know and I can put you in touch with him.
se
After telling him what you were looking to do, he sent me this photo:
An externally hosted image should be here but it was not working when we last tested it.
For this he just took a piece of cast acrylic, used some Krylon paint that's made specifically for painting on acrylic, and then lasered a positive image on it. As you can see it also includes halftone imaging so you're not limited to straight black and white.
In this piece, where the acrylic is lasered, it's frosted. He says that extruded acrylic can be lasered leaving it virtually clear ("hardly noticeable" he says). He also says that while he hasn't tried it yet, the same technique should be able to be done on glass with the laser power turned down sufficiently that it only vaporizes the paint and doesn't frost the glass.
You say you want the lettering clear, but unless you're going to use something like an EL panel for backlighting, it seems to me that backlighting would be rather problematic without something to diffuse the light.
With the acrylic or glass frosted, you already have a means for light diffusion without having to use a separate EL panel or milk glass to provide diffusion.
If you paint the panels yourself, this could be done rather inexpensively. He doesn't charge large setup fees and pretty much just charges for machine time.
If you'd like to explore this option, let me know and I can put you in touch with him.
se
By the way, here's another project he did that involved a piece of synthetic emerald.
First, he just took some masking tape and covered the front surface of the piece of emearld (which he says is about 3" x 5"). He then lasered the masking tape:
It was then sent to a friend of his who abrasively etched the exposed text through the masking tape:
The face of the emerald was highly poslished (you can see the reflection of his hand and camera in the photo) so the abrasive etching created a matte surface which provided a high degree of contrast.
Again, the piece is only about 3" x 5" and the typeface is only about 10 point. So even with abrasive etching, the lasering is able to achieve very fine resolution.
se
First, he just took some masking tape and covered the front surface of the piece of emearld (which he says is about 3" x 5"). He then lasered the masking tape:
An externally hosted image should be here but it was not working when we last tested it.
It was then sent to a friend of his who abrasively etched the exposed text through the masking tape:
An externally hosted image should be here but it was not working when we last tested it.
The face of the emerald was highly poslished (you can see the reflection of his hand and camera in the photo) so the abrasive etching created a matte surface which provided a high degree of contrast.
Again, the piece is only about 3" x 5" and the typeface is only about 10 point. So even with abrasive etching, the lasering is able to achieve very fine resolution.
se
Text by KBK?
In any case, screen printing on plastics is routine and easy. The soda machine stuff is usually done on polycarbonate, dashboard stuff likewise. Also CDs. For small legends (e.g., buttons and keys), pad printing is the method of choice.
I'm not sure about diy inks, but when I was doing this professionally, we had good luck with Nazdar for decorative panels and legends.
In any case, screen printing on plastics is routine and easy. The soda machine stuff is usually done on polycarbonate, dashboard stuff likewise. Also CDs. For small legends (e.g., buttons and keys), pad printing is the method of choice.
I'm not sure about diy inks, but when I was doing this professionally, we had good luck with Nazdar for decorative panels and legends.
SY said:
KBK?
Yeah, for those who are already set up to do it. Otherwise, he's gotta buy the screen, emulsion, ink, screen coater, squeegee, make a base for the screen, produce the artwork film, coat the screen, expose it, rinse it, then ink it up, screen the pieces, then clean up the screen and the squeegee if he expects to use it more than once...
On the other hand, he can just buy a can of Krylon Fusion in his preferred color, spray his pieces, drop 'em in the mail, and get them back all finished a short time later.
If he's going to use acrylic, he could use say plain 12 x 12 sheets, then the lettering can be done and the pieces laser cut in whatever shape he wants all in one operation.
se
No, that's good reason to do something else, but a screen print setup can be useful to have (confession: I don't have one any more...). Otherwise, it's pretty cheap to farm it out- there's lots of independent screen printing places in any town of size. Any of them will have the right screens, emulsions, and inks to do a job on sheet acrylic. Just another option.
Hmmm...this is getting annoying.
I've already got a perfectly good HP laser printer. Buying another printer just to do one or two pieces of plastic doesn't sound like a good use of pocket change.
I imagine that the photographic emulsion, ninety-nine step silk screen process would work too, but I'd end up with a lot of stuff and things left over. Again, wasteful. Sounds fiddly as all get out, too...which translates as time consuming and more steps for something to go wrong.
SY,
The buttons I'm describing aren't silkscreened. It's some sort of solid process, where the nomenclature is solid white plastic all the way through the thickness of the surface of the button, perhaps 1/16". I remember whittling a button like this with a pocket knife one time. It's either black all the way through, or white all the way through, depending on where you cut. The best guess I could come up with at the time was some combination of injection molding and extrusion, but I never bothered to research it. Note that I'm not saying that it would be economical to have one or two plates run off by this process, I'm just trying to collect ideas. Who knows what will come up?
Steve,
The laser thing is of potential interest, but it sounds like I'd need a bi-color plastic, black & clear layers--not undoable, granted (hell, guitar pickguards have as many as four or five layers). Your observation about diffusion is correct--my default plan is to use a clear front, laser printed negative image of the words, and a translucent white back plane to handle the diffusion. Actually, to be more particular, I'll use several separate white pieces, one for each word, and paint/Magic Marker them along the edges to eliminate back/side scatter of the light, so that if one word is lit the others stay dark. Translucent white plastic would give a smoother, more even "texture" to the backlighting, although I can see how someone might prefer a more granular texture.
Grey
I've already got a perfectly good HP laser printer. Buying another printer just to do one or two pieces of plastic doesn't sound like a good use of pocket change.
I imagine that the photographic emulsion, ninety-nine step silk screen process would work too, but I'd end up with a lot of stuff and things left over. Again, wasteful. Sounds fiddly as all get out, too...which translates as time consuming and more steps for something to go wrong.
SY,
The buttons I'm describing aren't silkscreened. It's some sort of solid process, where the nomenclature is solid white plastic all the way through the thickness of the surface of the button, perhaps 1/16". I remember whittling a button like this with a pocket knife one time. It's either black all the way through, or white all the way through, depending on where you cut. The best guess I could come up with at the time was some combination of injection molding and extrusion, but I never bothered to research it. Note that I'm not saying that it would be economical to have one or two plates run off by this process, I'm just trying to collect ideas. Who knows what will come up?
Steve,
The laser thing is of potential interest, but it sounds like I'd need a bi-color plastic, black & clear layers--not undoable, granted (hell, guitar pickguards have as many as four or five layers). Your observation about diffusion is correct--my default plan is to use a clear front, laser printed negative image of the words, and a translucent white back plane to handle the diffusion. Actually, to be more particular, I'll use several separate white pieces, one for each word, and paint/Magic Marker them along the edges to eliminate back/side scatter of the light, so that if one word is lit the others stay dark. Translucent white plastic would give a smoother, more even "texture" to the backlighting, although I can see how someone might prefer a more granular texture.
Grey
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.