[TheShirtBox]

I was just wondering if you guys put an outline or a trap on everything when separating colors in Corel? I outlined each separated page with a 1 pt. for the color that the film would be. So the total overlap would be 2 pt. if that makes sense... But I had some trouble lining it all up still because it was a really tall image, and when the top lined up the bottom wouldn't and vice versa. Just wondered how big of a trap or outline do you put on multi-colored jobs when lining them up by hand? Or at what point is the trap way too big and start to affect the look of the print? (I was using a flash for this particular 3 color print).

Thanks!

 

[tman07]

Nick,
If you have a 2 pt trap and it still doesn't line up correctly, you have problems elsewhere.

With film from an epson printer, you shouldn't need ANY trap if you have the following things in order:

1. Good press that holds registration
2.. Screens set up properly - level front to back and side to side
3. Good tension on screens
4. Proper screens (a 110 will lay down more ink
and allow the colors to lay against each other as opposed to a 230 mesh which lays down less ink.)

Hope this helps
Good luck!

 

[TheShirtBox]

It still registered ok, but I could definitely tell that there was more clearance for either the top or bottom depending on how I set it. I just was curious if people used a trap at all more often, or if people used one bigger than a 1 pt one. I just like trying to make registration easier on myself because I get sick of doing so many test prints, haha!

 

[PositiveDave]

By default the outline lies on the object edge so that a 2pt outline has 1pt inside & 1pt outside and gives a 1pt trap.

 

[tman07]

Ok, but in your original post you said the top lined up and the bottom didn't.

So I would suggest, reducing the trap alittle bit on the next jobs until you get the minimum amount of trap you feel comfortable with.

For me personally, I don't trap anything but a white underbase since I started using ink jet positives.

 

[TheShirtBox]

Well, when I had the top lined up perfectly (this was text with a black outline), I could see that it was an even overlap over the whole text, but at the bottom there was maybe a millimeter or a little less of the white shirt that would have been in between the text at the bottom and the outline at the bottom... I was able to even it out and it registered ok though without any gaps. I guess I'll just try to stick with a 1 pt. trap and see how things go. thanks!

 

[Ken Styles]

Hi,
What type of exposure set-up do you have? It is possible that your light source is not casting a true shadow of the film onto the screen and is shifting a bit. You should try to register the positive to the screen after you wash out to see how accurate it is burning.
Do you notice as the sun moves across the sky, the shadows of poles move? But the pole do not move, it remains stationary. The light source is just shining on it at a different angle.
So when you line up the screens on press, the actual burn will perfect on some areas but not perfect in other areas. This can happen alot with box exposure units with multiple lights sources as well as single light source that is too close to the screen during the burn.
For a larger design you may have to to move your light source further away and burn longer.
You need to make sure that the film is burning into the screen straight and true so the image washes out exactly like the film.

 

[ZenPrinter]

Hi,
What type of exposure set-up do you have? It is possible that your light source is not casting a true shadow of the film onto the screen and is shifting a bit. You should try to register the positive to the screen after you wash out to see how accurate it is burning.
Do you notice as the sun moves across the sky, the shadows of poles move? But the pole do not move, it remains stationary. The light source is just shining on it at a different angle.
So when you line up the screens on press, the actual burn will perfect on some areas but not perfect in other areas. This can happen alot with box exposure units with multiple lights sources as well as single light source that is too close to the screen during the burn.
For a larger design you may have to to move your light source further away and burn longer.
You need to make sure that the film is burning into the screen straight and true so the image washes out exactly like the film.

I have experienced the same thing at times. I don't have an ink-jet (wish I did). What I have found even using a laser jet is I can run edge to edge if I follow a proceedure I have learned. We don't need to get into that here.

Meantime 1pt. is good. I run an auto and what I do is line up the top and lock it in and fudge the bottom over till it lines up and lock it in.

Lately I have slowly, due to cash been replacing all of my wood screens with static aluminum Sefar frames.

Today I set up a four color on polyester tech shirts. EVERYTHING is backed in white due to poly sublimation issues. I have 4pt text and grapichs surrounded by 1 to 3 pt borders. Lines up perfect and the detail even with reversed text holds.

Not sure what I am trying to get across here except I wish I had an ink jet and more of these frames. I print everything with 230's. 110's are...

Yes you must have a single point light source.

Hmm, What else? Level platens, squeegy and flood bar, with just the right amout of pressure on both.

Humidity is a problem.

Screen Printing is rocket science/finesse and there are no magic buttons.

Get good frames/mesh and line up your screens to your art, not a print of one of the colors.

Tri-lock is next.

 

[TheShirtBox]

I have that Ryoexposure unit? The aluminum one that is like 25x36 or so. It has the compression lid and I use a piece of foam with black felt on one side of it to try to get the best exposures. It does seem like the lights are close to the glass but I am no expert on that. I think I will try your idea and see how the washed out image compares to the film. Maybe there is another factor in all this somewhere...

But I do have a question about something you said, Zen.
"Get good frames/mesh and line up your screens to your art, not a print of one of the colors."

Now most of these frames are brand new, BUT what do you mean lining up the screen to the art instead of the print of a color? My usual technique is to print the biggest color first and line up the rest of the colors to that, is there a little better order to do it in?

 

[dogprinter]

By default the outline lies on the object edge so that a 2pt outline has 1pt inside & 1pt outside and gives a 1pt trap.

This is a man who knows what his business is. When you convert outlines to curves it really show's what's going on.

 

[dogprinter]

Well, when I had the top lined up perfectly (this was text with a black outline), I could see that it was an even overlap over the whole text, but at the bottom there was maybe a millimeter or a little less of the white shirt that would have been in between the text at the bottom and the outline at the bottom... I was able to even it out and it registered ok though without any gaps. I guess I'll just try to stick with a 1 pt. trap and see how things go. thanks!

Is you off contact good? If it's not even from the front to the back you will not be able to have good registration. You could also have warped pallets which never helps either.

 

[TheShirtBox]

Yeah, maybe the tilt wasn't perfect. I do have trouble with the tilt sometimes because it sticks.

But I'll just stick with a safe regular 1 pt. outline.

 

[ZenPrinter]

I have that Ryoexposure unit? The aluminum one that is like 25x36 or so. It has the compression lid and I use a piece of foam with black felt on one side of it to try to get the best exposures. It does seem like the lights are close to the glass but I am no expert on that. I think I will try your idea and see how the washed out image compares to the film. Maybe there is another factor in all this somewhere...

But I do have a question about something you said, Zen.
"Get good frames/mesh and line up your screens to your art, not a print of one of the colors."

Now most of these frames are brand new, BUT what do you mean lining up the screen to the art instead of the print of a color? My usual technique is to print the biggest color first and line up the rest of the colors to that, is there a little better order to do it in?

When you line up to a print of your first screen the squeegy pressure/pull will be off to the rest of the screens. When you line up to the art on the platen there is no pull so they will all be in the same place.

 

[Ken Styles]

When you line up to a print of your first screen the squeegy pressure/pull will be off to the rest of the screens. When you line up to the art on the platen there is no pull so they will all be in the same place.

What do you mean? Shouldn't they still line up to a print if your screens are clamped into the press tight?

watch this video

[MEDIA]http://www.youtube.com/watch?v=T-HZYo74T_Y[/MEDIA]

 

[TheShirtBox]

That's a neat trick!! A good way to save on test pellons haha. I always end up doing so many test prints when I set up multi-colored jobs...

 

[ZenPrinter]

That's a neat trick!! A good way to save on test pellons haha. I always end up doing so many test prints when I set up multi-colored jobs...

That is a neat trick but whats the point you still have to micro register. Besides what about all those wiping cloths? I don't even have pellons.

Again I put my art/film positive squared and centered on a platen. I put in a screen and lock it in. Move the platen/art to where the screen image is. Line up the register marks on the screen with the ones on the art using micros. Do the same for each screen. Move the platen back to where it is supposed to be. Done. Start printing.

 

[TheShirtBox]

so would you just put down the biggest film and line everything up to that one? or do you use the other films for the other colors to register it too? I suppose lining it up to the biggest part of the print would make sense. Just takes place of printing the biggest part first and lining everything up to that...

 

[Ken Styles]

The orginal problem here I think is that the image on screen was not an exact mirror of the image on the film.
Therefore, you would need to line up the prints from the screen, not from the film.