Platemaking

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Hello -

I have a couple of questions about platemakers. I currently use Boxcar for all of my platemaking. I’m always totally satisfied with them, but would love to do everything in house. My cousin is a scientist and told me he could give me a UV lightbox that he has lying around in his lab. I don’t know any details about it, but it does have a timer and projects UV light. Does anyone know if I could outfit something like this to make photopolymer plates?

Also, would something like this be suitable for photopolymer platemaking? No idea. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=150638678808&ssPageNa...

Any help would be appreciated! Thanks!

Nicole

No problem Anna, happy to

No problem Anna, happy to help.

I know how much of a pain having to double transparencies can be. That’s what I had been doing as well but I was getting frustrated because I couldn’t get very good detail on my plates, especially if I wanted to print tiny letters or lines or anything like that. So I finally broke down and spent some money on a good printer and good film ink. Let me know if you need any more advice.

Joey

Hey Joey, just wanted to say

Hey Joey,

just wanted to say thanks! I think for now the walmart [we don’t have walmart in the NL, but I think HEMA will suffice] space saver bags will do the trick. Thanks for the tip about the little towel. I checked out some vacuum sealer systems for the kitchen and they had nice clear bags to work with so that would be a good alternative but a bit pricier [starting at € 120]

I’m also going to try your inkjet modification for the films too. I’ve been using inkjet transparencies [printed on my epson] doubled up and it’s worked well, but it would be much nicer not to have to match up the 2 transparencies. It’s a pain.

Joelanich,

Thanks for the tips. I love the idea of making one’s own vacuum table. But my uv unit is HUGE and really heavy so there’s no way I can mount it upside down without some serious hardware.

Do you have a link to these laser engraved plates? What’s the average cost of an A4 laser engraved plate?

thanks,
anna

I made a vacuum table to

I made a vacuum table to hold the film to photopolymer. I cut an 1/8” deep grid pattern in 3/4” mdf with a circular saw and drilled a hole in the center through the mdf to accept a hose barb. I then hooked a vaccum pump up to the hose barb and covered the top of the mdf with kreene. The film and photopolymer was then placed between the kreene and the table and a vaccum was pulled. It works great.

For exposure I used the made a light box with the following items:

(6) Bulbs: http://www.topbulb.com/find/Product_Description.asp?intProductID=44099

(12) Sockets: http://www.1000bulbs.com/product/5314/SOCK-L13357U.html

(1) Ballast:
http://www.1000bulbs.com/product/2176/BF-WH8120LC.html

I then mounted the light box above the vacuum table (which was on drawer slides) and it worked nicely set up. I used an electronic timer for the light so I could precisely control the time.

The setup worked great but the darkroom work for the film and the hand washout was a pain, so now we laser engrave a direct engrave photopolymer.

I hope this helps!

Hi Anna, You would think

Hi Anna,

You would think weighing it down would be enough with a heavy lid and box but it’s amazing how tight the film has to be to the polymer to get a good exposure. It sure surprised the heck out of me.

I am not really sure about the kitchen seal unit, I have seen the material used to seal food and it’s textured and cloudy, unless they make something else I just haven’t seen.

I tell you what worked wonders for me before I had the actual plate burner was a “as seen on tv” vacuum seal space saver bag. I will have to double check which sizes I bought but I believe I purchased a large and extra large. They use a very clear plastic so it doesn’t interfere with the exposure.

They are available at Walmart and I think the largest bag was only $7.

The problem I ran into with the space saver bags is there is a white stripe (graphic element) on the bags, but it’s pretty easy to avoid, especially with the larger bags. So I just put a small bathroom towel in the bag under the vacuum valve (otherwise you won’t get much suction because the top of the bag will just suck and stick to the bottom side) and put my polymer and film on top of the towel. Seal the bag and vacuum. I love these because they hold a long seal and it’s very tight. And you can use them over and over again, I even put a hole in one on accident and just covered it with duct tape and it still worked great.

Let me know if you have any other questions or concerns. I am happy to help.

Joey

Hey Joey, Thanks so much for

Hey Joey,

Thanks so much for the reply! So if it’s not the glass it’s definitely the way the plate and film are sandwiched to each other and the glass. I’m embarrassed to say that I’ve been taping the plate to the film and then placing them on the glass, with a heavy lid on top and an even heavier box on top of that. But I guess I should have known that wouldn’t fly.

I’m thinking of getting one of those kitchen vacuum seal units? I’ve always wanted to try sous-vide cooking. I figure 2 birds one stone.

Whaddya think about this?

Thanks for your help.

best,
anna

Hi Anna, I feel your pain,

Hi Anna,

I feel your pain, I have had to deal with my fair share of plates coming out poorly through all the experimenting I have had to do but believe me, there is hope.

I don’t think it’s the glass. My homemade unit uses 1/4” window pane glass that I got from Home Depot and it seems to work just fine. I keep my plates about 3 inches from the bulbs when exposing. I also recently acquired a very nice but “older” plate burner from a local printer closing up shop for $50.00 and the glass covering the vacuum seal on it I know for sure is even thicker than the glass on my homemade unit. I still use my homemade unit for the post exposure so as to not burn up the nice metal halide bulb in the plate burner.

I know you mentioned your picture frame method (very genius by the way) for when you didn’t have glass for your unit, but now that you have glass what are using to sandwich your film to the plate?

douglasmward,

I was nervous about not having the RIP software but it turns out you don’t need it. It’s really only necessary if you want to screen print halftones, but for photopolymer plates which mainly uses solid colors, you can easily do without the expensive software. I also do screen printing so I may have to purchase it someday but for my letterpress printing I just need solid black for my film output to expose my plates.

All I do is design my work and save it as a .pdf and I can make little tweaks to the print settings to get a VERY DARK result. I mean, it’s extremely black, the waterproof R-film is great too, the ink adheres to it very well. I am only printing from 4 cartridges and getting great results. I basically just “tricked” my printer into thinking it’s printing color, but actually the cartridges are all filled with black ink.

Let me know if you have any other questions.

Joey

Hi 87Volcom, And everyone

Hi 87Volcom,

And everyone else. I recently built a UV unit. Ordered the prescribed bulbs directly from the plate manufacturer and had to build the fixtures too as the wattage/size combo was not something available. [40 watts/60cm] And then built a 6” high wooden box all around and placed a ledge on all 4 sides for the glass and cover to sit in. See attached pic.

Before I purchased the glass and cover though, I started exposing my plates by placing the film on top of the plate and then sandwiching that between a thin piece of picture frame glass and the back of the frame. My little exposure sandwich is then secured by heavy duty clamps. The clamps were wide enough to balance between the frame edges of the box and therefore hold the “sandwich” over the lights.

Worked like a charm. But I finally got my glass [a sturdy piece of non-uv glass] cut to size for the frame and my heavy wood box top too.

Now the exposures are coming out like rubbish. There’s a definite spread with the light. The lines aren’t crisp at all. I believe it’s the glass. Maybe it’s too thick? [about .5 cm]

What type of glass do you use for your unit?
And about how far away do you position the plate/film?

I can always go back to what I was doing before, but I would prefer to be able to use the entire bed for exposure, in case I want to do a poster or expose multiple plates at once.

Ideas?

thanks,
anna

87 Volcom, how do you make

87 Volcom, how do you make the Epson 1400 print black from all 6 print cartridges? Does the printer still think it has multiples colors. Silkscreeningsupplies.com sells a rip for just this. But I dont think its necessary. Not sure though.

A few other things… If you

A few other things…

If you want to try my “rustic” approach to platemaking you must be sure to buy Unfiltered UV black lights. These are not typically found in your local hardware stores or Lowes, I had to go to a specialty light bulb store to find them. Normal fluorescent lights won’t work as they do not put out enough UV light.

Attached are a couple photos of the box I built out of scrap wood. You can really build it out of pretty much anything, as long as you have light fixtures and a sheet of glass above it it should work no problem. I would also recommend putting hinges on one of the side walls for easy access to the bulbs if one burns out or something.

I would also recommend putting a hinge top on it so the box is completely closed when the lights are on. I was told these lights are pretty safe to be around when they are on but just to be on the “safer” side it might be a good idea to avoid a lot of exposure.

Now this method works for me, but it is a bit “rough” and has taken quite a bit of research to figure out. Using a space saver bag to seal the film to the plate works GREAT but it is a bit awkward. I like my method because I am not producing several plates a day. I letterpress print mainly for enjoyment and if I make a buck here and there then it’s great. But if you are on a tight budget like myself (broke college student) then it might be worth a shot.

My film output process is

My film output process is similar to what a personal screen printer might do. I have an epson 1400 photo printer coverted to print all black very opaque dye based ink. And I use R-film from silkscreeningsupplies.com. I bought empty ink cartridges for the printer with auto reset chips on amazon so I just fill them with any type of film ink, also available at silkscreeningsupplies.com, throw them in the printer and it’s ready to go. Directions on this are all over YouTube. Its great because I get very dark crisp results.

For my exposure box it’s 25x25 inches to accept 2 24inch fluorescent light fixture units (each one holds two bulbs) for a total of 4 24inch bulbs inside the box. I wired the fixtures to a standard household lightswitch and put a piece of glass inside the box about 3 inches from the bulbs. The walls of the box are about 8inches high.

After I design my artwork and print it to film I vacuum seal the film to the plate with a space saver bag (walmart for 5 bucks) throw the bag on the exposure unit and flip the lights on for about 6 minutes. And that is my platemaking on a budget.

Step-by-step details on how

Step-by-step details on how to construct such a box with a materials list would be a great help to the newbies on the list.

I work for a flexo plate

I work for a flexo plate manufacturer and we’ve done some testing with the ASPECT Quadra. It prints inkjet on ink-receptive film. The idea is great, I’m sure it would work well with letterpress, but as for flexography, we’re unable to hold anything below a 7% circular dot at 85lpi on a finished liquid plate. I realize, most people aren’t printing process color separations with a letterpress, so this shouldn’t be a problem. Anyways, as for the artwork you typically see with letterpress, I don’t see this being a problem.

Yeah, details would be great

Yeah, details would be great here. As far as the film and the actual exposure unit/process.

87volcom, how are you

87volcom, how are you printing your film?

I built an exposure unit for

I built an exposure unit for 30 bucks and it works perfect for my photopolymer plates. It uses unfiltered UV blackIights and exposes my plates in a few minutes. I have a hard time spending thousands of dollars on a plate maker when I could make one myself. May not look as fancy but it does the job. I even figured out a way to print good quality film for pretty cheap.

A platemaker designed for

A platemaker designed for exposing RELIEF photopolymer would have a bank of UV or blacklight tubes just inches from the exposure plane. It is possible to use exposure units intended for exposing offset plates, many of which do have photopolymer emulsions, but the exposure times for thin offset plate emulsions and relief plate emulsions are very different. So offset plates can be exposed with a point light source, or tubes with lower UV output, but using these for relief plates the exposure times will be very long.

Out of interest, what would

Out of interest, what would the ‘the real deal in terms of a platemaker’ be? I’m looking at platemakers here in Europe at the moment, what makes a good one?

Thanks for the advice.

Thanks for the advice. I’ll stick with boxcar until I can afford the real deal in terms of a platemaker.

Nicole Stay with Boxcar if

Nicole

Stay with Boxcar if you are satisfied with their plates. You will not be able to produce any better with this device.

Gerald
http://BielerPress.blogspot.com

Good question. According to

Good question. According to the ad, its used for its: “ability to expose paper, plastic, and aluminum offset plates” All of which are relatively thin. A photopolymer plate can typically be anywhere from .04 to .06 inches. Meaning the surface exposed will be closer to the bulbs, which could potentially mess up your exposure. Then again, I’m no expert. It would be nice to see the manufacturers specs.

Also, it looks to be only a UV exposure unit, I can’t imagine there being a washout unit on it too.