Why 600ppi instead of 300?

[Dottonedan]

People have read about my use of 600ppi for files and a few members here are also using 600 as well.  Below, sort of explains why this higher resolution works for these specific types of files for screen print more so than 300. Especially when needing to choke an underbase or very thin line work.

The 300 letter T doesn’t really show the benefits in this example. By the time I had to resample down to 72ppi, for uploading here, it doesn’t show how thin the top serifs are. This would be all that much harder to burn and hold in the screen. Often it is broken up, not exposing the thin lines at top. Even more so with smaller type. This type is done at about .5” tall.

The 72ppi is not something that any of us would ever use for screen printing (I don’t think), but sometimes some people might try to use what was given to them without adding more "art rebuild time” and can look horrible on press. But it makes for a good example of one extreme to the other.

For screen printing, the only real benefit of higher than 600ppi like 1200, is that it would help to create the smaller dots (1-10% dots) to look more round versus pixels. But the reality is, that you can’t tell at that range, by the naked eye, if it’s a nice round 3% dot or if it’s a 3 pixel shape.
Once printed with wet ink, smashed onto a tee shirt, another 1-5 screens smashed over top of that, it’s hard to know if that was a nice round dot, or a 3 pixel shape. Therefore, I don’t see much more benefit coming from a 1200dpi printer than a 600dpi printer.

Now Laser to screen. That, is a whole other beast...and does make perfectly round small dots (or as near as you can get). The SATTI laser has an option to do an equivalent to 2540 dpi.  What this does...for me, (since I said that anything over 1200 is not really that beneficial in the end result) is that the Laser, with that ability, would enable you to do exceptionally high lpi such as 85-100 lpi and maintain the desired tonal range you are looking for across the board. With 1200 and 600, it’s a bit harder and you have to fake it.

[ZooCity]

Sing it brother.

600ppi/dpi is the min. for quality screen printing work imho and should be the starting point, the baseline.   

How are things going along with the Saati laser?  (don't mean to derail)

[Dottonedan]

Sing it brother.

600ppi/dpi is the min. for quality screen printing work imho and should be the starting point, the baseline.   

How are things going along with the Saati laser?  (don't mean to derail)

Funny you should ask. I just had a conversation with Ben Petsy today.

I’ve read that the LED Lasers last over 10,000 hours with 100% efficiency. That’s roughly 5 years. It’s advertised that there are no consumables with Laser, as there is no INK or WAX to be used. LED laser light does ware out after time. A Wet ink print head, can last 3-6 years on average. I’m not sure what a Wax print head will do these days but it’s better than it used to be in older models due to excessive heat on the heads over along period of time. I think that could be said to last near or as well as the wet ink. So print heads last 3-6 years “typically”. and Laser lights last 5 years. How much is it to replace all laser lights. If you do one, should you also do all of them since they will eventually all go out some time soon at that point?  Did I misrepresent anything?

Ben replied:
"at any given time there are roughly 60-75 of the lasers that are actually in use depending on which unit you choose and the size of the image. That said, and out of say 96 lasers (with the 6080 horizontal) you have roughly 20 lasers as “spares” before you actually have to purchase a laser, which costs about $200 each. It isn’t necessary to replace the entire array when one burns out."

It comes with a 2 Yr warranty.  I don't want anyone to think that the answer, was a ding against the SAATI LTS in any manor.

The reason being, that this LASER REPLACEMENT expense alone, is about the same as you would have with WAX or WET ink consumables in the long run. Then the print head cost is another factor that you will eventually have to work in there also. So the total cost of (if you did) replace all of the lasers, it would not be anything more than you would over time with the other options.

Wet ink cost per Ltr. $177.00 x 1 Ltr every 2 Months (guess). x 12 = $1062 Pr Year. x 5 Yrs = $5310.00  (consumption changes per shop). Could be half that over 5 years or could be double for some.

Cost Pr M&R Wet ink heads should be in the area of $1300 per print head. Not sure what the WAX print heads cost. Anyone? So for the I-Image S, you only have 1 print head to worry about while the other models can have as many as 3.

I just googled and the Kiwo XTS Wax, 1kgPrice: $354.00. Again, I don't know what you get out of that...but I had seen posted a couple times that the cost of Print heads and cost of wax were pretty close between Wax and Wet ink with wet ink just a tad less.

Actual usage and expenses for each shop will be different than others.Now, ONE more thing about the SAATI.  With that LASER, and those TOP level screens you can get from them, They are (to me personally), the BEST so far. This is a result past any 600 or 1200 DPI wax or wet ink machine. I just don't see yet, how anything can compare.

Dmax?  Nailed it. No issue obviously.

Dot shape? Nailed it.
Exposure time? Nailed it (while imaging).
For dot gain control (as it pertains to all of the other factors for dot gain), that is something that needs looked into more carefully. I think I heard some mention from SAATI representatives at some point that they were looking into options, but as far as I remember, there were no quick or easy methods to adjust at output. All gain compensation would rely on the separator providing the file to the machine for the gain control. That means your artist need to be able to do that well in the art. They can, and should, but not every production artist does that well.
Total imaging and exposure time? Iffy for a single imager, but having it print two screens at the same time, Well now, that's another story and to my mind, now puts that in the running with the more economical machines.
Laser certainly is something to really consider hard. Don't just pass it by on price alone. The price is worth it to you.

[inkman996]

I am not a fan of using an arbitrary number such as years for guesstimating the life of a print head. Years does not mean anything if one shop barely uses the machine or another shop uses it 8 hours straight every day. Just like in commercial equipment they use hours not miles or years, the hours are based on actually running time, excluding the time the machine is not running. I would prefer to see a counter system that counts the actual amount of time the print head itself is firing, that would give a far more accurate life expectancy to then be able to better compare the life of a print head from one shop to the next.

A salesman could easily tell a potential customer that he knows of one shop that got 7 years out of his print head but neglect to tell you that shop used the machine a couple times a week. What he will not tell you is that another shop he knows that uses the machine 8 hours a day only gets one year out of each print head.

[GraphicDisorder]

Knock on wood, our i-Image is still on its original print head. 2014 Model.

[inkman996]

Knock on wood, our i-Image is still on its original print head. 2014 Model.

We are two years in and have some missing spots, but it still prints well enough. My guess one more left in it.

[Dottonedan]

Knock on wood, our i-Image is still on its original print head. 2014 Model.

We are two years in and have some missing spots, but it still prints well enough. My guess one more left in it.

.


The thing about “missing spots”is that you do have to address those when you see them. Same day. Clear those out. How to do that...is in your manual in the Maintenance section about (Daily maintenance). A nozzle check should be done (every day) to assure there is no issues with a few blocked. When you see them, do a couple  auto cleans and test again. If still there, Switch the black ink...to the PINK cleaning solution and follow the instructions step by step to flush that line to get black ink out...fill with pink ink the lines till the entire line turns pink. Then, with the pink filled, set ink valve to print...and then do a couple more auto cleans (using the pink through the heads). This is a degrading solution and will help break up any dried ink in the jet. (be sure to follow the procedures in the manual exactly).


It’s possible to continue on with your day, and it will print and cover looking and exposing just fine...but it’s not covering 100%. What happens over time, is that (those few spots) get harder and harder to clear out or become clean. The first few days, it may just be an air bubble blocking those few jets. So you let it go, assuming it may work it’s way out. A few wks later if you’ve not done anything about those, “they spread” into the adjacent jet, and then perhaps ink lays on top of that bubble, but it’s not going anywhere, and begins to dry and become not just an air block, but a dried jet. If this sits in the head, it can get worse and worse, and spread and spread...and this is why a head can go bad in a year or two.


Typically, you can bring most clog issues back to life with the pink cleaning solution. It’s been my experience that I’ve been able to bring them back. Some very easily, and some take more time with repeat procedures. I think I’ve had to replace print heads at about 4 of my 300 shops.

[inkman996]

Knock on wood, our i-Image is still on its original print head. 2014 Model.

We are two years in and have some missing spots, but it still prints well enough. My guess one more left in it.

.


The thing about “missing spots”is that you do have to address those when you see them. Same day. Clear those out. How to do that...is in your manual in the Maintenance section about (Daily maintenance). A nozzle check should be done (every day) to assure there is no issues with a few blocked. When you see them, do a couple  auto cleans and test again. If still there, Switch the black ink...to the PINK cleaning solution and follow the instructions step by step to flush that line to get black ink out...fill with pink ink the lines till the entire line turns pink. Then, with the pink filled, set ink valve to print...and then do a couple more auto cleans (using the pink through the heads). This is a degrading solution and will help break up any dried ink in the jet. (be sure to follow the procedures in the manual exactly).


It’s possible to continue on with your day, and it will print and cover looking and exposing just fine...but it’s not covering 100%. What happens over time, is that (those few spots) get harder and harder to clear out or become clean. The first few days, it may just be an air bubble blocking those few jets. So you let it go, assuming it may work it’s way out. A few wks later if you’ve not done anything about those, “they spread” into the adjacent jet, and then perhaps ink lays on top of that bubble, but it’s not going anywhere, and begins to dry and become not just an air block, but a dried jet. If this sits in the head, it can get worse and worse, and spread and spread...and this is why a head can go bad in a year or two.


Typically, you can bring most clog issues back to life with the pink cleaning solution. It’s been my experience that I’ve been able to bring them back. Some very easily, and some take more time with repeat procedures. I think I’ve had to replace print heads at about 4 of my 300 shops.

We do a test print every date, date it and throw it in a folder so we have a good record of what is happening. The couple jets that blocked up happened back when we were super slow due to covid, I tried to keep the machine active every day but missed a few for sure. I will give the pink solution cleaning a shot and see if that gets those few jets cleared out thanks.

[Dottonedan]

I am not a fan of using an arbitrary number such as years for guesstimating the life of a print head. Years does not mean anything if one shop barely uses the machine or another shop uses it 8 hours straight every day. Just like in commercial equipment they use hours not miles or years, the hours are based on actually running time, excluding the time the machine is not running. I would prefer to see a counter system that counts the actual amount of time the print head itself is firing, that would give a far more accurate life expectancy to then be able to better compare the life of a print head from one shop to the next.

A salesman could easily tell a potential customer that he knows of one shop that got 7 years out of his print head but neglect to tell you that shop used the machine a couple times a week. What he will not tell you is that another shop he knows that uses the machine 8 hours a day only gets one year out of each print head.

• Personal preference really.
I remember that about you. You made a reply post years back, about me using percentages as examples that were not facts.
I am a fan of averages or rounded figures to give or receive and educated guess. (when the work to get an exact or real figure) is too difficult or time consuming for the need of the answer. For example, if the answer being and average would not hurt the end result.  We can say that many shops or a large portion, or 60% of the industry uses SAATI mesh. It could be pretty accurate to say, "very few or less than 2% of the industry uses Tektomi mesh from my expereince”. Here, you are quoting an individuals personal experience. That alone, is subjective but the info could be coming for a good source so we have to look at that. Here, one is implying or illustrating the idea that very very few are using Tektomi mesh. How few? If I had to guess, it would would be like 2%. Not literally, just an educated guess.

When you know, the majority of shops were and are, still running the same print heads, then you can make an educated guess at the longevity  M&R now reports that their heads will last (on average) or approximately at least a year or more. That to me, is a legal and corporate answer, trying to avoid anyone assuming a guarantee. (To error on the side of caution), but is by my own experience, not a close representation at all and now, aside from my own experience, we still commonly hear of shops having print heads that are in use over 5-6 years when asked. The negative things are often overshadowing any good. When a head doe snot last, everyone hears of that.

• Yes, indeed each shop is different and the more savvy printers will know that each shop is different and will show different usage results.Having said that, there are still "averages”.   For example, "How many prints can you get from a gallon of ink"?  A ink supplier can give you and average base don X and X. As we all know, that depends on how it is used, what mesh, how many strokes, etc.

• On your machine and all M&R I-iMage machines, there is a counter. This is on the LCD panel just under your keyboard. Use the arrow keys to see just how many prints the print head has printed. This also counts any and all prints such as (while at the factory during testing). A brand new printer from the factory, may have 30-60 prints on the counter. This counter will count the number of total prints and the number of total exposures separately for the life of the machine.

[inkman996]

Using a year is still to inaccurate even if you try to use averages. Our industry is not really all that big and the sample size to determine an average is lacking.  A year is simply based off of age and not actual usage, I could have a 30 year old Volvo 160 excavator with low enough hours on it that I know the under carriage is not ready to be replaced, or have a 5 year old 160 with so many hours on it I know an under carriage is due to be replaced.

I do see the counter and even that is not close enough in my opinion. there is many sized prints being printed. The most accurate would be like I mentioned actual in use time. Its really not all that important because print heads are not the same in price as under carriages on an excavator, I just mention it because I feel it is to easy of a thing for a salesman to take advantage of when they are one on one with a customer. What the company lists is one thing  but what the salesman will tell you is always going to be padded to their favor. I know M&R says 1 year on the print head, but I  was also told based off of our screen turn over per week we should expect 4 or 5 years.

[Dottonedan]

I can relate. Understood.

[zanegun08]

I was going to reply in a previous thread but I didn't hit post since the other post was in relation to scaling halftones after creation, but in summary, I don't think achieving a perfect circle has much to do with your final print, it's more that the value of color is showing correctly.

The 300 vs 600 gets you a better shape in photoshop yes, but then how that translate to your film / CTS, then to Emulsion / Mesh, and then Ink to Shirt you won't see a noticeable difference in my opinion unless maybe looking under a microscope at the shape of the dot which means nothing.

I think you could have banana shaped halftones, or poop emoji, and if it translates the correct amount of value to your substrate from a normal viewing distance the effects will not be distinguishable to 95% of the population.  Also, majority of images that need halftone works are photographic, if you are just upscaling a 72 PPI image to 600 PPI, you aren't gaining any resolution.  So yes, better circles on the computer, but does that actually translate to better prints if the source image didn't already have that information.

More time should be spent for better separations, knowing your dot gain and creating tone curves to compensate for that average, better inks, knowing that your printer is going to just mash out the pressure.  A perfect circle means nothing to me when it has to go through a square mesh anyhow. 

Sure higher PPI is better in a lab, but I think of people in India on table top presses with loose mesh screens and no automatic presses putting out great looking work, and it brings me back to the real world

[Dottonedan]

Ditto.

I agree totally. The only real area were high rez above 1200dpi really benefits is in the ability to represent the small dots (more accurately) than a 600 or 1200 would.
THIS area of question is in the extreme ranges o shadows and highlights.  At a low 600, that rez cannot produce the full dot needed to make the correct tonal %. That is not about "shape" but is all about content. Those dots do not contain enough structure to correctly account of a 3% dot. It can't. So, as you do go up in rez, you get more accurate tones in the shadows and highlights.

Consider this.
Most thought that the 600dpi or even the 1200dpi WAX machines were kicking out superior dots. "They look more rounded". I agree. More so than wet ink.
But, when you consider the 2540 rez, of a Laser. It's near dead on exact. If I gave the laser machine a 600dpi 1 bit tif file, to produce (at any of it's levels of DPI output, It would produce a more exact representation of that 600dpi dot shape. That being of a dot made up of 3-4-6 pixel grid squares. Same thing at 1200dpi 1 bit tif files.  It's able to reproduce the tif exactly as the source file with hard, sharp vertical emulsion walls. When you look at these small dots of the WAX ink at 600 or 1200, It's not. It' can't produce that shape "correctly".  Yes, it looks rounded, but that is not due to the WAX RIP or printer. A 600dpi 1 bit tif is a 600dpi 1 bit tif . The "roundness" shaped like a meteor, you get is due to the inability to produce that exact shape because it's WAX and not a laser or a wet ink.  It's for this reason of the inability, that the wax dot actually looks good to us like we can use it better than the 3-4 pixel squares. I am believing that the 1200dpi WAX, is not better than the 600dpi WAX. That's all sort of another offshoot of your topic.