# Dot size for screen printing



## bigbang (Mar 21, 2010)

Hi,

I am trying to find the size of a single dot (in micrones or any other unit) that comes from a fine screen (for tshirt printing).
I am not interested in LPI,DPI or halftones just to find out the dimensions of 1 dot.
Is there a table that shows it for different mesh counts?

Thanks


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## mrbadexample (Jun 8, 2009)

Maybe I don't understand your question. The dots will be the same on any mesh. Are you interested in the size of dots at 10%, 15%, 20%, etc? Because LPI affects that, as well. And the dot will change depending on those percentages.

Can you clarify?


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## PositiveDave (Dec 1, 2008)

Generally you want your mesh (in inches) to be around 4.5x your lpi.
A 50lpi halftone has a cell size of 508microns, about half a millimetre.
A 50% 50lpi dot has a diameter of around 400 microns, assuming simple round dots (which no-one uses).


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## CNClark (Mar 2, 2010)

Are you asking for the dot size on the film. Or how large the opening is in between threads in the mesh? If it's the latter...all mesh companies will have a mesh opening table for each mesh count and thread diameter.


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## bigbang (Mar 21, 2010)

Thanks all for the answers,

I will try to explain what I'm after:

The dot size is the diameter (dimensions) of the dot on the tshirt. That dot comes out from a single hole/opening in the mesh where no lines are formed only a single dot (if you put many dot you will get a line). 

Think about a mesh that has only one hole/opening open and it can print a single dot only.

I am interested in the range of dot sizes that I can get such as from a 155, 230, 305 and 355 mesh.

Thanks


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## jsf (Aug 4, 2009)

I am not sure what you are referring to, but here is a table in which a ratio is usually used to help in the selection process and can be calculated by dividing the mesh count by the line count (both numbers must be in either inches or centimeters).









(credits: Grafica Flextronica)


Or perhaps, you can read more about on mesh openings here: Pre-Press 3


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## bigbang (Mar 21, 2010)

Thanks.

So what is the correlation between that and the dimensions of a dot on the garment?

I think I can ask it in another way:
What is the thinest line - a single line fron a single colour I can form from a 230, 305 and 355 mesh?

Thanks again


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## jsf (Aug 4, 2009)

bigbang said:


> Thanks.
> 
> So what is the correlation between that and the dimensions of a dot on the garment?
> 
> ...



As a procedure, halftone is a technique to make gradients. The smaller i gets the lighter it will print. In a non-technical answer to your question in my opinion is to do it right as long as you can do your halftones as finer as it gets... In screen printing sometimes you cannot be that static and specific.

We do some 30lpis on 100mesh count and even on a 120 mesh count, 40lpis to 50lpis can be applied on 150, 200, and 250, 55lpis to 70lpis are applied to 305s.

And in our experience the finer dots the better details you can get and the finer dot you can print the less moire effect is noticed. The best yet we have is 65lpi on 305s, doing 70lpis is very hard to perfect when it comes to washing but it is still achievable.


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## bigbang (Mar 21, 2010)

So how many micrones is it: around 10-20, 40-50, 90-100 or 140-150?

I am looking for the finest line or dot.

Thanks


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## jsf (Aug 4, 2009)

bigbang said:


> So how many micrones is it: around 10-20, 40-50, 90-100 or 140-150?
> 
> I am looking for the finest line or dot.
> 
> Thanks


I am not sure how I can answer you... but if you have read the link from my previous post: Pre-Press 3, as stated:

_*8. Mesh opening*
The dimensions of the mesh openings affect stencil support, meter ink flow and contribute to the print's appearance._ 

_The best mesh for screen printing is commonly woven out of monofilament polyester and it functions both as support for the stencil and to meter the amount of ink deposited on the substrate. The dimensions of the mesh count, percentage of open area and thread thickness all contribute to the appearance of the end product. You will find that accurate measurements of these mesh specifications are supplied by the manufacturer. Poor image registration, image elongation and uneven ink deposits can result from the improper selection or preparation of the mesh fabric._ 

_*Mesh opening*_

_As a general rule, the dimension of the mesh opening should be at least three times larger than the pigment fineness of the ink._
_ The mesh opening is measured with a microscope from the edge of one thread across the opening to the edge of the opposite thread, in microns (1 micron = 1 millionth of a meter, or 0.00003937"). High quality mesh is woven so the finished product offers a perfectly square opening, within tolerances. Since threads come in different diameters, you can have mesh openings that are the same in vastly different mesh counts. A fat thread in a low mesh count can have the same mesh opening as a thin thread in a higher mesh count. The threads will make the mesh thicknesses different._

_*Percentage of open area*_

_Percentage of open area (POA) is more useful when calculating ink consumption. The percentage of open area, or aperture percentage, refers to the relationship between the thread area and the actual opening between four woven threads in the mesh. The open mesh area helps determine the ability of an ink to pass through the mesh, as well as the thickness of the ink deposit in the printed image._
_ Textile printers don't use percentage of open area as much as those who print non-absorbent substrates such as glass, plastic or metal. The absorbent nature of our substrates provides great latitude, so the subtleties of choosing a mesh based on POA are not as significant._


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## jsf (Aug 4, 2009)

Now even if you actually knew on how many microns(if this will make you feel comfortable instead of using LPIs) you really wanted to print on... I mean is that really makes a great deal of relevance?

Why not just give it a try making 100lpi (very fine dots) halftone on a 355 or a 70lpi on 305... Now the question is can you do it successfully from exposure to printing? (Hmmmmmm, I difinitely doubt it )


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## bigbang (Mar 21, 2010)

Thanks again for the answers.

This I what I am talking abot: The dimensions of the fine dots (100lpi (very fine dots) halftone on a 355 or a 70lpi on 305) on the tshirt or the smallest spot in microns I can get from the screen. 

100lpi (very fine dots) halftone on a 355 or a 70lpi on 305: What is the thickness of the line in microns or inches?

Whre can I find this information?

I know digital printers have a very small drop diameter (on the tshirt) but each printhead has a different one.


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## jsf (Aug 4, 2009)

bigbang said:


> Thanks again for the answers.
> 
> This I what I am talking abot: The dimensions of the fine dots (100lpi (very fine dots) halftone on a 355 or a 70lpi on 305) on the tshirt or the smallest spot in microns I can get from the screen.
> 
> ...


Here's a sample of a separation, embedded it in Corel... print this on laser and on a plain paper or vellum. It contains a 65lpi, 85lpi, and 100lpi halftones. 

See if it does answer your query... Goodluck.

MEGAUPLOAD - The leading online storage and file delivery service


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## bigbang (Mar 21, 2010)

Thanks,
It is important as I need to compare it to digital printing. I am not a screen printer yet so I dont know what 100pli is. I sit 100 lines per inch so each line is theoretically 1 inch divided by 100? Is a line made of a row of single openings? I just need to know the range of dimensions of dots/lines from different mesh.


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## URUMEX (Nov 6, 2015)

Hi, I am trying to print on pvc film font sizes 0.2 mm. Anyone knows how to do it?


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