Who is doing the seps? It sounds to me that your trying to control it or do it in-house. I would recommend you farm out the separations this way you can be given direction from the separator. All emulsions will hold halftones if exposed properly and you have good film along with the right mesh count. You can't just save a file in cmyk, print them out, and expect them to be perfect. It takes talent to know what something will do when you get to press. Even having good seps and screens it takes some know how what you need to do on press. I'm sure most printers don't use stock CMYK out of the ink containers, you need to look at the print and cut down color until you have the right balance of all colors to create the colors you want to end up with. Then after you have everything perfect from all the above you have to keep the prints looking consistent from the 12th print all the way to 1000 if not more. You mention that your scanning a canvas painting, you can't scan it and expect to have good seps this way you need to have someone take a high Rez photo and have them give it to you in a transparency then scan that.

What's your set up? What kind of film output device are you using? What LPI are you using? What mesh count did you expose on? What kind of exposure system do you have? What kind of press? Manual or auto? Why not stick to spot color or spot process?

 

All good questions, I don't know what kind of press I have but there is a way to search my older posts I put I picture of it before, I have an Epson color 3000 printer, used 55 lpi last time tried a run, 1000 watt mh exposure no vacuum 305 or 230 mesh, and the reason I don't stick to that is because my art is a lot of realistic stuff and more than my 6 color press will handle plus I can't figure it out yet either. I can say that one of my huge problems has to be something to do with the fact I can't get my halftones to expose, has to be. and I wouldn't know where to out source separation but I have every Sep software availableincluding separation studio. any advice ill be happy to take.

 

Ok. You can still do the seps if you want but I would still recommend you find a local source or someone who freelances but for now you just need to do some learning but you need to start with consistency, starting with everytime you do a process job let's stick to one mesh. 55lpi your going to want to stick to 305 mesh and if your having issues with holding halftones drop your Lpi to 53 this will help, small change but you will get better results with your set up. Don't know what emulsion your using but I would recommend a high end graphics dual cure emulsion this will help you capture great detail 1 that comes to mind is Kiwo Poly Plus S but that's up to you. Not sure how your exposure unit is set up but if it's a home made system just make sure your distance is correct measure you frame diagonal multiply it by 80% that's how far the light should be from the center of the light to the center of the frame. If it's a professional exposure system no need to do this but remember if the light is further away it will add time. Make sure you have a good sandwich: glass, film, screen. Expose a dual cure with a 1K MH light at about 3.5 minutes but I would do an exposure test and adjust. If possible, not sure if I understood you correctly that you have a 6 color press, why not add 2 spot colors example: if you need a 186 C red then use a spot for this so you don't have to sacrifice other areas where you need to maintain the color from shifting and having to double pass and muddy it up so use a PMS 186 but cut it down 50% with a transparent base. Yes it's kind of cheating but nobody is grading you, it's making it so you can get to the end result easier. Sharp squeegees help probably 75 duro if your doing it in manual and I hope you have nice flat pallets not warped due to flashing etc. It's so frustrating having to press harder or useing a softer squeegee trying to get it to print in the center of the pallet. Not trying to be a smart *** just being honest. Again, I hope this helps but you will get it just stay consistent with how you do process or any process in your business, yes it's important to adjust as you learn but once you have something that works you just repeat it.

 

Chucky,

there are several steps involved in printing simulated or four color process. Simulated is easier and more forgiving, you should start with it.

all the components are like a chain, if one link fails, everything fails. It is not an either or, but must have all of it!

1. art- good art makes it easier. starting with art that is proper format is very important. bad art usually produces bad prints. Get your images converted to electronic format at high res and correct color.

2. separations. While not widely known, just as important as the other links in the chain. Bad seps will make it very difficult to print and can make it almost impossible in some cases. Separations are a lot more than splitting the colors. Good separator will know the limitations of ink build up on whites vs the underbase. 'will mix the colors on the shirt and underlay or overprint with other colors for effect. They also take into account how the print is going to run when large quantities are printed. They will change the laydown or print order to reduce the ink build up and provide color consistency.

3. printer. This includes the prepress (films and screens) and the printing part itself.

• PREPRESS: RIP: I tested several RIPs with densitometer on two different popular EPSON printers. Two of the three were printing dots 10-15% to big. It made it easier to get teh ink through the screen, but the color balance is off. If trying to match a piece of art or printed material, having halftones that are of by that much gets to be pretty difficult.
• FILMS: Bad films will produce bad screens, will produce bad prints. To get good prints, very fine lines and halftones must be printed clearly and the films have to be dark. Weak films do not allow proper exposure and the edges of the halftones suffer. Again, the dots might gain 10% and the color will be off.
• SCREENS: Simulated and four color process take advantage of inks mixing on the shirt. Some shades require very small amounts of secondary color and if fine halftones can not be held, those colors are not obtainable. For example, rose gold is a combination of yellow and 5-6% red. If one can not print a 5% half tone dot the only way to achieve this color is to print it in a separate screen. WHen low percentage halftones can not be achieved, any color transitions will be abrupt and in stair-step fashion rather than gradual. Simulate process is a little more forgiving here than the 4CP. From my experience, 9% dot will produce acceptable simulated process work and 6% would be the minimum for decent CMYK. Simulated will be grainy but acceptable at 45 lpi where the smaller dots are easier to hold. 4CP just looks to grainy and should start at 55 for good smooth results.
• PRINTING: you will need parallel plattens, low off contact and sharp squeegees (75-80 durometer). Screens should be in pretty good shape. Statics are fine, just can't be beat up. Off contact has to be low, you should print with one stroke only and the angle should be pretty close to upright.

To get started, hire somebody to separate for you and provide films. It will remove many of the unknowns and let you concentrate on the printing part. The guy I use held my hand as I was learning and I even hired him for a consulting trip, but I am on a tangent . . . separator will help you with mesh choices, squeegee blades, angles, mesh selection, print order . . . It would be almost impossible to figure all these out on your own.

I will gladly answer any questions you might have, but unfortunately I can not hold your hand through it. I spent thousands of hours and tens of thousands of dollars learning, practicing and getting it right. It is a process you have to go through to get good at it. It is not difficult, and there is no mistery, but it is time consuming to get to be good at it. You do not need a lot of money to get there, but small investment will save you considerable amount of time and frustration.

So start slow and take one step at a time. Outsource the seps in the beginning and take advantage of their knowledge. If you have a job that needs to be separated, ask the separator to include some sort of halftone testing film with the seps.

Read about proper coating of the screens, then do the step wedge test with the provided film and repeat it several times. In one weekend you can fine tune your screens and get it to where you can hold the dot needed for the simulated process. If you stick with it and work on it few days in a row, you could be printing simulated process that is good enough to sell to your customers a week from today!!!

pierre


p.s. you will need a vacuum exposure unit for good results with fine half tones. If you really had to, you can build one yourself for few hundred bucks.

 

Pierre, thank you for all you great advice. I will defiantly use all the advice you have given me. The only thing is even if I wanted to have someone else do my seps I haven't been able to find anyone in Colorado that does it. I have looked for help with these things, and although everyone on this site is very helpful, it isn't so out here. I did go to one place that was willing to give me a tour of there place and look at a set of film I exposed to try to see what I was doing wrong but was told they looked fine so I assume it is in the exposure where I am going wrong. I am in the process of building vacuum unit so I hope that helps. I plan on getting some different emulsion just to take that out of the equation. I will try a few things you suggest and let you know. Thanks a million

 

try Dan at dot-tone http://www.dot-tone.com I use him. You can also google screenprinting separation services and find companies that will do it for you. They do not have to be in the same city as you.

 

Yeah, it sounds to me like you need a vacuum for your exposure. Just the slightest warp in your screen will allow light to get around the stencil and hit your screen in ways you don't want it to. I was blown away with the results I was able to get once I started using a vacuum exposure unit.

Good luck!

 

Well I'm waiting for the neoprene to come in then i will be able to try it. Tried the pond stuff and it really sucked trying to get it to glue down on the corners. Hopefully you're right, I hope it makes a huge difference. thanks

 

Thay looks like a promising place to get stuff done, thanks!

 

Instead of using glue to attach your vacuum blanket, you should secure it with some kind of strips screwed down over the top of the edges. It'll make it easier to replace should the need arise. Just a suggestion.

 

i finally got my vacuum unit put together and i did it like you said. man i have to say it makes a HUGE difference having the vacuum!! i just did my first test run with it and the detail i got on my screen now is amazing!! the difference is unbelievable. i was one of those guys that says "pile 50 lbs of weight on it and it will do just as good as a vacuum unit" wrong!!! unbelievable!! thanks a million for the input on that. i am gonna go do a test run with these screens now so hopefully it turns out good. i have yet to have a good shirt so i have a feeling this is the one

 

Man, I got my neoprene lastnight and I think its way to thick!! I am having a Hell of a time trying to fasten it to the wood frame and there isn't room for the screen its so thick. what size neoprene are you using and do you know a place to get it. I got mine on eBay

 

The frame in the picture used pond liner. The pond liner needs quite a bit of slack, but on my commercial unit with wetsuit material, there is a good amount of sag. Sounds like you might have bought a piece that was exactly the size of your frame.

 

to expose, i lay the screen on glass with positive underneath, then i put a piece of foam on the screen, then a plywood board on top of foam, and put weights on top of the board. im a beginner at halftones but have gotten good results from the get go. ive done good 1 color halftone images. the highest mesh i use is 156 and i think thats the reason i lose the tiny dots so im sure once i get my 305 mesh screen i will be in business!!! i too am about to get started in cmyk process. i have a question though:

i have a workhorse odyssey. its all metal and very heavy duty. i was doing some spot color on a 50 run job, halfway through, on of my colors shifted a little bit towards the left. keep in mind i was doing a double pass: one flooded push stroke and one non-flooded pull stroke. there may very well have been some slightly loose hardware. aside from that, how does everyone feel about the push stroke, or doing both consecutively???

 

Looks like your using a MH bulb, make sure you cut a few vent holes add a fan for in and a fan for out. You don't want to start a fire.

 

yeah its a 1000w mh. i dont leave it unatended because it does get really hot. i was thinking of putting a fan but i didnt know if it would effect in any way. so i am assuming that since you are saying that that it wont effect anything?

 

thanks. i hope to one day be able to make enough money off of anything i am doing to buy all the right stuff. i havent sold but just a couple shirts as of right now. i just cant seem to get things dialed in. i made a big step in the right direction last night with a halfway good run. i need to figure out a good way to get the boxy look out of an image that i did so it will look good on a shirt. here is a pic of it.

 

nice work Chucky!

the first exposure unit i used was a home built one and it didn't have a fan but we were using florescent lights. those still heated up the glass a fair bit and this caused some issues with film shrinking and warping. as other forums members mentioned adding a cooling system will help allot.

 

So how big a fan do I need? I'm gonna gave to rebuild eventually because I want to be able.to.do bigger screens and what I got now barely fit. A fan is going in before I fire it back up though, I ran myself out of all chemicals. So I got a second before I can run again. Thanks to everyone for all the good advice.

 

Nothing really big just small fans to keep a good airflow, like little desktop ones.

 

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and last since i know everyone is tired of reading, you know what this site needs, a chat thing like gmail has or yahoo. something where we can talk directly instead of having to wait a week for a response if you are like me and have a shirt on the platen right now and are just waiting for some advice because you dont want to mess anything else up

We actually do have that feature It's the big "CHAT" button on the left hand side of the screen when you visit the website.

The challenge is...most members here have businesses to run and come on here when they have a spare moment. So they help when they can. Those times may not be the same time that you have a t-shirt on your press, so they may not have the time to help out in live chat.

By posting questions in the threads and answers in the threads, you get help, and the 100's of people who read this thread later in a similar situation as you also benefit from the help that gets posted (instead of the help disappearing in a chat window or hidden away via an email or phone call). That's what makes this place great for sharing info!

PS. If you have any more forum suggestions, it's probably best that you post them in the Feedback section of the forum, PM or email me