Author Topic: Halftone file for DIY films/screen testing and some pointers on calibration  (Read 20839 times)

Online Homer

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P - do you usually print bidirectional? I always thought that was a no-no. I am going to flip my numbers as you suggested and see if that helps with the gains. I cranked up my resolution to the maximum and it cleaned up all the spatter but it still doesn't have a clean defined edge like yours. I'm using the same printer so I suppose that's the difference between Fm and accurip. I'm still loosing it around 90%, it goes straight to mud.
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Offline blue moon

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P - do you usually print bidirectional? I always thought that was a no-no. I am going to flip my numbers as you suggested and see if that helps with the gains. I cranked up my resolution to the maximum and it cleaned up all the spatter but it still doesn't have a clean defined edge like yours. I'm using the same printer so I suppose that's the difference between Fm and accurip. I'm still loosing it around 90%, it goes straight to mud.

we switched to bidirectional about a year ago and have not looked back. Seeing the difference now, I might go to 2880 single direction for the super high end prints, but will stay with 1440 bidirectional for rest.

AR starts getting muddy in the 90's, that's the limitation of the software (from what I have seen). It can be cleaned up by calibrating, but at the end FM does look better. The question is, how much better?

pierre
Yes, we've won our share of awards, and yes, I've tested stuff and read the scientific papers, but ultimately take everything I say with more than just a grain of salt! So if you are looking for trouble, just do as I say or even better, do something I said years ago!

Offline Screened Gear

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The dots I posted were 55 LPI with no improvements or edits to the rip. I am using a canon IPF 650.. I ran that print on silkjet film. I took the picture with a USB microscope at 800 zoom laying the film over white paper. Even with all the stray dots the film come out. With smooth dots. The stray dots are so small they don't come out. I have been using filmmaker and the out put dots are much more like Pierres dots. I just ran Pierre's file on Friday real fast  with ghost script before leaving for the day. Film is an area you really need to put some time in. Good dots and dark films make the biggest noticeable increase in print quality in my opinion.

Offline Dottonedan

The dots I posted were 55 LPI with no improvements or edits to the rip. I am using a canon IPF 650.. I ran that print on silkjet film. I took the picture with a USB microscope at 800 zoom laying the film over white paper. Even with all the stray dots the film come out. With smooth dots. The stray dots are so small they don't come out. I have been using filmmaker and the out put dots are much more like Pierres dots. I just ran Pierre's file on Friday real fast  with ghost script before leaving for the day. Film is an area you really need to put some time in. Good dots and dark films make the biggest noticeable increase in print quality in my opinion.


Hi Jon,  I'm not sure, but my guess is that the fact that your dots look smoother when exposed, is telling us that you essentually are losing detail and burning out our smaller dots. This is going to happen to a degree but should not be excessive. It would be more educational to see a good picture of that halftone are printed as well as your lowers end dots to see where you are ending up.
Artist & Sim Process separator, Co owner of The Shirt Board, Past M&R Digital tech installer for I-Image machines. Over 28 yrs in the apparel industry. Apparel sales, http://www.designsbydottone.com  e-mail [email protected] 615-821-7850

Offline Screened Gear

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I was just referring to the scattered dots in the film they are so small that you really can't expose

Offline Dottonedan

I was just referring to the scattered dots in the film they are so small that you really can't expose


Thats what I think you are underestimating. If the industry materials (inks, mesh, emulsions) we have available to us can hold the shape of a correct smooth ellipse dot shape of a 3% in a 65 line screen, it's more than possible to hold the contour shape of your rough edged dot. Another example (to the extreme) is if you have a true high quality (Photo film) imagesetter and you run your films faster at 1200 dpi, that dot shape is not (as well defined) as when using 2400 dpi.  Those who control 4 color process prints to a perfection can see the benefits of this 1st in the stencil and 2ndly in the print. How much, is probably not of a concern to the average printer...and of no concern at all to the purchaser but is a factor that is considered often timed by those who win many many awards. I know your not trying to win awards. It was more of an illustration to show that those small (often considered irrelevant) areas of spray...can play a part in your outcome.


Often, we confuse not being able to hold a dot that small (within the screen) or your light source. Actually we can hold a 1% in a 65 line screen just fine (in the emulsion). It's the ability to put it down on various garment weaves (and to what readable pleasant or acceptable degree to the eye) that people question.


So my point is, (and I'm only mentioning this for the technical discussion/benefit of the forum and just general chat) is to say that a rough edged dot shape like in the photo (in my experience) is also playing a part in your image quality. The rough edges add to your filling in at various parts of your tonal range. The outer (smaller fragments of dots) considered overspray (can also literally be held) if you have all of your other processes fine tuned.


If your intent is to under or overexpose so that you get a smoother dot. They contribute more so, to you not holding an optimal image quality than average. It's like using toner and that outer residue that shows up. Most can agree that toner does not give you a well defined dot shape...and so your mid to shadow range where the dots converge-converge faster. Resulting in more fill in (depending on how you handle the rough edges). Meaning, your FIX might be to either over or under expose...yet you might not know why you have done so, but you know you get a better dot shape as a result. This is probably why, but can also lead to shadows filling in or highlights burning out.


As a result, if you make adjustments in the screen burning process to open that up or fill it in more, (in an effort to get a smoother dot) you are also effecting your lower end dots or your shadow tone tones. One way or another, one side is effected. To what degree?  Well, thats all relative but I would guess that will determine wether you can hold a 5% dot better or worse.


What would be the fix?  I donno.  Maybe a better RIP or a different printer. I didn't read all of those details and I'm also not experienced at printing out from toner or inkjet printers and using those rips. I only can see the possible results of what they dot can or cannot do base don shape and density.  A tonal adjustment or linearization would not fix that issue, only add a band aid...but this is the most common fix.


Dot shape is probably the least considered, but you do hear more of edge definition when discussing the quality of various emulsions. This plays a part in that.


It's all often considered overkill for anyone not interested in controlling dots to perfection like Pierre, Rick Roth, Target graphics, Andy Anderson, Mark Coudrey and the like. I just thought I'd share my thoughts on this thread..and that image... and often times, it's not going to be of a concern or even impact the quality that much to the average shop.
Artist & Sim Process separator, Co owner of The Shirt Board, Past M&R Digital tech installer for I-Image machines. Over 28 yrs in the apparel industry. Apparel sales, http://www.designsbydottone.com  e-mail [email protected] 615-821-7850

Offline Dottonedan

As a side note, It's not like your current dot quality is poor. It's par for the average shop. Most all are using inkjet printers for films. but take for example, Mark Coudrey. If he were putting in a print for a competition, I'll bet he's going to use 2400dpit on his photo film imagesetter rather than the best inkjet printer.


On a scale of 1-10 regarding dot shapes and density.




Yours is a 6 and most seen in the industry. ( average ink jet set up) various rips.
Pierre's is a 8 and much better of course,    ( fine tuned ink jet set up) with a good rip.
Mark Coudrey's is a 10. (2400 dpi photo films)


I'll also say, for what it's worth, that Mark Coudrey also offers ink jet films of a higher calibre than average but still less than the photo film. So it's not like he will ONLY use photo films.
Artist & Sim Process separator, Co owner of The Shirt Board, Past M&R Digital tech installer for I-Image machines. Over 28 yrs in the apparel industry. Apparel sales, http://www.designsbydottone.com  e-mail [email protected] 615-821-7850

Offline blue moon

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just an FYI, Jon did say he uses FilmMaker the same RIP as we do, but the sample was printed through GhostScript. So my guess is his dot quality is significantly better than what he posted to help keep the conversation going . . .

Jon what kind of microscope did you use to take the pictures? I am in a market for one and that image looks pretty good.

pierre
Yes, we've won our share of awards, and yes, I've tested stuff and read the scientific papers, but ultimately take everything I say with more than just a grain of salt! So if you are looking for trouble, just do as I say or even better, do something I said years ago!

Offline Dottonedan

Yea, I don't wanna come off as a primadonna dot shape guru,  as in (use what I say or you're wrong). It's not that way at all.
Artist & Sim Process separator, Co owner of The Shirt Board, Past M&R Digital tech installer for I-Image machines. Over 28 yrs in the apparel industry. Apparel sales, http://www.designsbydottone.com  e-mail [email protected] 615-821-7850

Offline ebscreen

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Glad this thread came up. I had tried out AR and FM awhile back and was sold on AR
for some reason, but can't recall it now. I'll give FM another look.

Is FM networkable like AR is?

Offline blue moon

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Glad this thread came up. I had tried out AR and FM awhile back and was sold on AR
for some reason, but can't recall it now. I'll give FM another look.

Is FM networkable like AR is?

you can share the printer over the network. There is an option to create hot folders, but I have not used it.

pierre
Yes, we've won our share of awards, and yes, I've tested stuff and read the scientific papers, but ultimately take everything I say with more than just a grain of salt! So if you are looking for trouble, just do as I say or even better, do something I said years ago!

Offline Screened Gear

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Pierre,

I got the microscope off of ebay a year or two ago. I just did a search there and there is a ton of them. Mine is 20X-800X some are 40X-800X. Mine looks like the picture below. I think I paid $38 for it. Its cheap and has its issues but does a nice job for the price. Its great for looking at and getting pictures of ink deposit and dot shape. Its just another tool to have around.

Offline JBLUE

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I do not use Ghostrip so if this is a dumb question I apologize. Can you linearize that rip?
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Offline Screened Gear

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I do not use Ghostrip so if this is a dumb question I apologize. Can you linearize that rip?

To be honest with you I have never even looked at the settings. It worked so I just went with it. I just looked over everything and there is no spot to linearize it. I have used both Filmmaker and ghost on my  printer and FM does a ton better. FM has a ton of adjustments you can make that will effect the printer. With FM I can make the films super dark with standard ink. It also cleans up the dots. They are tighter and more refined. I think the part that I was not expecting was the dots are smaller. A 55LPI dot out of Ghost is larger then a 55LPI dot out of FM. Not sure if that's a good thing or not. Come to think about it, that maybe from the linearizing that is standard or preset in the rip.  I have talked to Pierre on this and the more you work with dots and adjusting your out put you realize how crappy your films were before. I still don't think the dot shape matters that much at a 55LPI but the darkness of the films and linearizing is the reason to get a good rip. Darker films wash out easier. They keep smaller dots from being overexposed. The linearizing will open up your gradiants so that your prints have more depth. It will also make printing easier and take less time to get jobs to print right.
« Last Edit: May 06, 2013, 05:26:40 PM by Jon »

Offline Inkworks

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Isn't the idea to linearize to the printed ink deposit, not the film? Or is that next to impossible to do on a shirt?
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