Before You Went LED, What Were You Using?

[Dottonedan]

We've successfully held the calibrated 4-5% dot at 55lpi on 330S mesh on the Vastex unit. Same thing with 3140 was holding 3%. BUT . . . . the exposure system was dialed in for the 3140 so changes in the RIP can be made to compensate for it. I am certain that with proper tools LED unit will expose 3%.

For anybody trying to see the calibrated 2% dot on a 305, it is not going to happen with ANY unit!!! As I understand, the physical limitation of the mesh is 3%. At that point the dots become too small to hold on. It would be possible to calculate the dot size and compare it to the opening size, but I'll take the expert's word on it. Anybody printing a 2% at 55lpi on a 305 and holding it is either not calibrated, on the wrong mesh or wrong lpi.

pierre

It's all relative to your specific device and setups. I'd guess that 90-95% of the industry produces printed apparel without a densitometer calibrated halftone LPI because of the cost to get one and the fact that they have been selling printed apparel without one for years. That doesn't mean what they print for halftone dots is truly correct, just well enough apparently.


Also, note that even with a densitometer, those calibrate (tone) accuracy and not size of dot accuracy. For example, an accurate calibrated 2% tone can still have a huge dot such as in a 20lpi. One mans 2% in a 55lpi is not the same as another. There will be people who can hold a 2% dot in a 55lpi on a 305 mesh (with their device). Of those, their dot is larger or closer to a 3% in another device.

From P,
the 20lpi was never part of this conversation!
If you take a look, you'll see that I SPECIFIED 55lpi and 2%. This creates a dot that has to be very specific in size and can be recreated anywhere in the world, by any piece of equipment and if it is 2% and 55lpi it will ALWAYS look the same!

(if it is compared to another 2% 55lpi that has also been calibrated, yes it should look the same).  Also, even yours, Your 2% 55lpi is not going to looks the exact same size as a 2400 dpi wet film processing imagesetter. Close, but not exact.

Anybody can print any size they want and as long as the print and the printing works out OK, nobody needs a densitometer.
  I would prefer everyone have and use one, but thats not the norm. I'm not saying they don't need one. They do. Everyone needs one. Getting them to get one is a different story.

Some ppl have a 2% dot in their art file, but when they actually develop the screens, it's 7%! They just held a 7% dot, not a 2% dot.   Well, that seems a bit extreme but ok. Could be.[/size]

[/size]

BUT as soon as you start saying that you can hold a 2% dot at 55lpi, that means only one thing.[/size]

  No. That means (someone printed a 2% dot in their process). It is their 2% dot. It is their norm (unless it gets calibrated), that is their gauge. They have nothing else to assign that areas except for where they started out being (2%). It's a 55lpi, It's 2% in the art so this (THIS) is our reference point...unless you have a densitomotor, It's held in the screen, it's printed on the shirt, it's presenting a nice award winning print (proven). For that person, thats the norm. That is the 2% in a 55lpi. Is it correct and truly a 2%. I don't think it matters since (something), some image data representing another color tone (was there). Will the customer ask for a refund if he finds out it was really a 3.5 or 4%?

[/size]

Also, holding a dot means (at least in my book based on what I was told) all the dots in that range have opened or cleared. By that definition, it is not possible to hold a 2% dot on the 305 as it is thinner then the mesh and will be lost when it lands on it.

pierre
[/size]

There's your problem. You restrict yourself to "definitions". You ever heard of impressionism? How about Pointilisim? How about faking it? As you indicated, you need 4% dots. Using 2% dots (I would safely try to make use of 3% dots) during production) but obtaining 50% or half of the 2% dots, combined with 3 -5 other colors of the same example, makes or represents a tone of another color. Correct?  Yes. So, sprinkles of 2% (lets say you hit and miss 50% of the dots on a color) CAN and does make an image representation. It's all about resolution.  These 2% areas broke up, hitting and missing, doesn't look great (when isolated and reviewed/compared to a given area of pretty solid squares, BUT, don't hate the fat people. We are people too. Everything has a purpose. Put those 2% dots in the art and you can make something.

[/size]I'm going to show you something here shortly. I have a bad memory for most things but for some things, (screen printing in particular), I have a good memory. So I will show you all something here as soon as he replies.

Re: the 20lpi.  Yes, (I said that). People do that now and then. They may say something (you didn't) ;) and put it in a post and reply (adding in various other things that other people have said in 2-4 more previous post combining them into one post. Is that so strange? I put it in the equations because earlier, prior to your reply, someone was talking about the size of a 2% dot being bigger or not accurate across the board. (There was a lot of that said).  Then even you mentioned "size" of a dot. The fact that you specified 55lpi or not doesn't pertain justifiably to make an argument here. What I said, applies to every line screen (when you compare a 55 to a 55 or a 62 to a 62 etc. to another device). This is before you even get to burn it, wash it out and print it. Again, if you want to have them equal, then yes, someone else's device would have to be calibrated...and the one being compared would also have to be calibrated...and only then would you be sure that they are as accurate a possible...and the 2% would be a 2% (but only on all machines calibrated) across the world. Like I said. Most don't get theirs calibrated and if you calibrate for someone, that doesn't mean it will be true 6 months later and you must calibrate (to the printed dot on the shirt), not the film results from a machine.

I agree. As I stated, some peoples devices put out a slightly thicker/bigger dot (even tho it's the same line screen) than another device. So yes, thats due to it not being calibrated with a densitomotor.

[inkbrigade]

Sorry.. couldn't resist.

[Racer Tees]

Sorry.. couldn't resist.

This is me.  Been fighting exposure for way too long.  Read through this thread and others on LED many times now.  Starlight should be on the way next week.

[Logoman]

His Premier