# DIY or Mimic Step Wedge Tests



## NFrancis (Oct 9, 2013)

Hey, just wondering if there is a way to mimic the stouffer or any step wedge test / calculator through ps or ai? I see that it's a gray scale but don't know the opacity increments to increase on each step.


I just ordered a stouffer 21 step test form FLS but won't receive it until after this holiday weekend. Need to test new emulsion asap.

Thanks!
Nikki


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## williekid (Apr 22, 2009)

You can get one free offline. check on this site I know they have one free for sure. How to Determine correct screen exposure times using Vellum


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## williekid (Apr 22, 2009)

which emulsion are you using and what is your type of light source?


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## sben763 (May 17, 2009)

You can do your own step wedge test. A Stouffer strip contains special film and can be handy but doing a step wedge test with films from you printer will produce the best test.


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## NFrancis (Oct 9, 2013)

williekid said:


> You can get one free offline. check on this site I know they have one free for sure. How to Determine correct screen exposure times using Vellum


Thanks.. I will deff consider this one.


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## NFrancis (Oct 9, 2013)

williekid said:


> which emulsion are you using and what is your type of light source?


EconoRed I Compact Production Infrared Dryer
Ryonet HiFi Photopolymer Emulsion

and Ryonet WBP Hybrid Emulsion Gallon for Water Based & Plastisol

Thanks
Nikki


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## NFrancis (Oct 9, 2013)

sben763 said:


> You can do your own step wedge test. A Stouffer strip contains special film and can be handy but doing a step wedge test with films from you printer will produce the best test.


I just watched a few videos on using your own films as a step wedge. Would that method help me determine if I am under/over exposed?


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## sben763 (May 17, 2009)

Yes. You start with a guess say 2:00 then add 30 sec each step. I'm going to do a video maybe later tonight in this. It is the best way to determine exact times.


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## NFrancis (Oct 9, 2013)

sben763 said:


> Yes. You start with a guess say 2:00 then add 30 sec each step. I'm going to do a video maybe later tonight in this. It is the best way to determine exact times.


So what if I place an opaque sheet over, lets say a half tone film and a spot color side by side, and expose every 30 seconds each step. Would that suffice?

Also, I've only used the stouffers strip once and I know 7 is the sweet spot for emulsion. So with that in mind, What am I looking during washout with this method? 

Nikki


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## williekid (Apr 22, 2009)

General recommendations. 500 Watt Halogen, 12-13 minutes. Unfiltered UV Black light. 4-5 Minutes. Metal Halide: 250-280 Light Units 
If using halftones id say cut the light by maybe a 1-2 minutes. I have not experienced the red emulsion but being a dual cure its similar to qx1 I believe. These light timings are just about accurate give or take. Don't really think you need a step wedge, but if you do use one start around these timings and move every 30 seconds or so. Hope this works for you. Also what type of light source are you using? You posted the type of emulsion and a dryer type.


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## sben763 (May 17, 2009)

williekid said:


> General recommendations. 500 Watt Halogen, 12-13 minutes. Unfiltered UV Black light. 4-5 Minutes. Metal Halide: 250-280 Light Units
> If using halftones id say cut the light by maybe a 1-2 minutes. I have not experienced the red emulsion but being a dual cure its similar to qx1 I believe. These light timings are just about accurate give or take. Don't really think you need a step wedge, but if you do use one start around these timings and move every 30 seconds or so. Hope this works for you. Also what type of light source are you using? You posted the type of emulsion and a dryer type.


You can't just give times like that. And proper exposure times require 0 adjustment for halftones. Different dual cures have different times as dual cure is either photopolymer and diazo or SBQ and diazo and those 2 will have totally different times. As well as bulb age and hours of use as well as how many times it's been started. The halogen and metal halide wear quicker when started and stopped many times. The unfiltered blacklights are more time dependent. Humidity and temperature will change times. In my shop humidity is 35-40% and temp is 68-70F during exposure.


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## williekid (Apr 22, 2009)

Those timings were from ryonet for that specific emulsion as directed by their website. If you go to the link posted you will see the times they recommend. That's why I asked what light source was being used. Much is depended on the factors of the environment but I can only give my input on the information provided.


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## porkchopharry (Mar 4, 2012)

I've found Ryonet's timing suggestions never worked for me as they are too general. WBP on my UV exposure is a 7 minute exposure. Can't imagine what it would be with a halogen work lamp.

A lot also has to do with coating method and technique. I use the glisten method which usually translates to 3 coats on the shirt side and then 2 on the ink. 

Conversely, with the same coating method, Saati Textil PV is a 60 second exposure.


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## sben763 (May 17, 2009)

I under stand but there is no way for anyone to know how much usage the OP bulb has. Humidity and temp shop conditions and so forth. I personally have done tons of research including getting a PC microscope to further dial in times and the effects of conditions. The diffrence between 40% humidity and 50% can be several minutes depending on the light sorce. The Hi-Fi emulsion from above is a pure photopolymer and requires to be 40% or lower humidity during drying and at least 2 hrs before exposure. The WPB is a dual cure of diazo and photopolymer and 45% during during and under 60% afterward before exposure. Pure photopolymer is more temper mean to humidity as it will reabsorb humidity even after dry if above 40%. The dual cure seems to be ok until about 65%. I have gone through many, many gallons of the Hi-Fi and a few of the WBP. I now just buy Hi-Fi and add diazo if needed for a water base or discharge product.


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## porkchopharry (Mar 4, 2012)

sben763 said:


> I under stand but there is no way for anyone to know how much usage the OP bulb has. Humidity and temp shop conditions and so forth. I personally have done tons of research including getting a PC microscope to further dial in times and the effects of conditions. The diffrence between 40% humidity and 50% can be several minutes depending on the light sorce. The Hi-Fi emulsion from above is a pure photopolymer and requires to be 40% or lower humidity during drying and at least 2 hrs before exposure. The WPB is a dual cure of diazo and photopolymer and 45% during during and under 60% afterward before exposure. Pure photopolymer is more temper mean to humidity as it will reabsorb humidity even after dry if above 40%. The dual cure seems to be ok until about 65%. I have gone through many, many gallons of the Hi-Fi and a few of the WBP. I now just buy Hi-Fi and add diazo if needed for a water base or discharge product.


I'm agreeing with you. There is NO way to determine somebodies exposure times. Too many variables as you mention. Coating technique/stencil thickness, humidity, light, bulb life, etc. 

What I am saying is that the exposure times you read on a site really have no bearing to the user's environment. 

My mention of my exposure times is to illustrate that point. Ryonet may say that a dual cure should expose in X amount of minutes - not for me. And a pure photopolymer in X amount - not for me either on that one. 

I also agree on the humidity thing. I will usually switch to WBP in the winter. And Textil PV in the summer. However, the last couple batches of WBP have not been too good, so I'm rocking Textil PV this winter.


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## sben763 (May 17, 2009)

porkchopharry said:


> I'm agreeing with you. There is NO way to determine somebodies exposure times. Too many variables as you mention. Coating technique/stencil thickness, humidity, light, bulb life, etc.
> 
> What I am saying is that the exposure times you read on a site really have no bearing to the user's environment.
> 
> ...


Lol. I was replying to the post above you. This page was up on my iPad and I didn't refresh the page. I also use the Saati PHU as it is also very similar to the HI-FI except it is water base and discharge capable without a hardener or diazo. I really don't like using diazo if possible.


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## porkchopharry (Mar 4, 2012)

I figured after I posted that you were referring to the post above. At least we agree though right?  And I wasn't trying to be argumentative, just agreeing. 

The PHU tell me more about it. I think I read it was very thick? I don't like using diazo either. It came in handy though when I was a little more green and needed to hone in my exposure and coating skills.

So the PHU is a quick exposure emulsion that can handle water based, plastisol, and discharge?


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## sben763 (May 17, 2009)

Yes we agree. I only be argumentative when I believe bad info is posted and then just try to give the best possible info I have from actual experience and not what I've read or heard. 

The Satti chem PHU is plastisol, water base and Discharge compatible with post exposure. I'll set the screens in the sun for 15-20 min minimum but usually longer. When doing runs up to 150 I just use after post exposure. If doing much more I'll have used CCI hardener up to runs of 500 and still able to reclaim. The photopolymer reclaims so much easier then diazo. The downside is humidity really effects this stuff. I coat and store 24 screens at all times and don't run dehumidifier all the time. I have to turn on a few hours before exposing screen in order to keep consistent times. Mant suppliers will send you a pint sample which should be enough to dial in and test. It comes in blue and pink. I personally prefer the pink. I was sent 2 gallons of blue and not going to use the second gallon but its more of a old eyes don't see as well though the blue to register a job. Otherwise their identical.


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## NFrancis (Oct 9, 2013)

williekid said:


> General recommendations. 500 Watt Halogen, 12-13 minutes. Unfiltered UV Black light. 4-5 Minutes. Metal Halide: 250-280 Light Units
> If using halftones id say cut the light by maybe a 1-2 minutes. I have not experienced the red emulsion but being a dual cure its similar to qx1 I believe. These light timings are just about accurate give or take. Don't really think you need a step wedge, but if you do use one start around these timings and move every 30 seconds or so. Hope this works for you. Also what type of light source are you using? You posted the type of emulsion and a dryer type.


We are using EXPOS-IT Ultraviolet - 40 Watt H.O. bulbs 28". Sorry. I don't know why I put the dryer.


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## NFrancis (Oct 9, 2013)

porkchopharry said:


> I've found Ryonet's timing suggestions never worked for me as they are too general. WBP on my UV exposure is a 7 minute exposure. Can't imagine what it would be with a halogen work lamp.
> 
> A lot also has to do with coating method and technique. I use the glisten method which usually translates to 3 coats on the shirt side and then 2 on the ink.
> 
> Conversely, with the same coating method, Saati Textil PV is a 60 second exposure.


Hey Andy, do you use your coating method for all screen printing applications? What are the benefits of repeating coats? Also, I am assuming numerous coats will change your exposure time?


Thanks Nikki


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## NFrancis (Oct 9, 2013)

sben763 said:


> You can't just give times like that. And proper exposure times require 0 adjustment for halftones. Different dual cures have different times as dual cure is either photopolymer and diazo or SBQ and diazo and those 2 will have totally different times. As well as bulb age and hours of use as well as how many times it's been started. The halogen and metal halide wear quicker when started and stopped many times. The unfiltered blacklights are more time dependent. Humidity and temperature will change times. In my shop humidity is 35-40% and temp is 68-70F during exposure.


Could you explain 0 adjustments for halftones. Not sure what that means?


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## porkchopharry (Mar 4, 2012)

sben763 said:


> Yes we agree. I only be argumentative when I believe bad info is posted and then just try to give the best possible info I have from actual experience and not what I've read or heard.
> 
> The Satti chem PHU is plastisol, water base and Discharge compatible with post exposure. I'll set the screens in the sun for 15-20 min minimum but usually longer. When doing runs up to 150 I just use after post exposure. If doing much more I'll have used CCI hardener up to runs of 500 and still able to reclaim. The photopolymer reclaims so much easier then diazo. The downside is humidity really effects this stuff. I coat and store 24 screens at all times and don't run dehumidifier all the time. I have to turn on a few hours before exposing screen in order to keep consistent times. Mant suppliers will send you a pint sample which should be enough to dial in and test. It comes in blue and pink. I personally prefer the pink. I was sent 2 gallons of blue and not going to use the second gallon but its more of a old eyes don't see as well though the blue to register a job. Otherwise their identical.


Sean, you're an awesome person and a very valuable asset to the community man. You're very generous with your tips and it's really cool. You are way ahead of me in you techniques, but like yourself, I try to help with my experience and what I learn on the way including my mistakes. It's always best to be honest and I appreciate what you do. I may give that PHU a shot when I run out of PV. I prefer pink too. easier to see like you said.


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## sben763 (May 17, 2009)

After you have your exposure times dialed in. There is no need to adjust your exposure times for halftones, this will make it a greater chance to blow off halftones if you expose less time. 

FREE Screen Printing Exposure Calculator here is a good exposure calculator and a good explanation on how to use. basically after you follow instructions which ever step gives you the best results is close to your target time. To further nail your time you can retest and use a narrower time like 5-10 sec. after you wash out go over you screen after it is dry with a magnifying glass or a loop and really look at you edges cause although it may look good from a foot away when looking up close choose the one with the smoothest lines as a jagged edge will indicate under cutting which is over exposure and common with your type of exposure unit but you can still do amazing work with that exposure unit as I had a similar unit for the first 6 years in screen printing


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## porkchopharry (Mar 4, 2012)

NFrancis said:


> Hey Andy, do you use your coating method for all screen printing applications? What are the benefits of repeating coats? Also, I am assuming numerous coats will change your exposure time?
> 
> 
> Thanks Nikki


Hey Nikki,

Yep I use that method for all my prints. I'm going to be honest when I say that after 2 years I STILL struggle with screen coating at times. That's because I don't do print jobs. I do all my own stuff that I sell on my site and through retailers. So...I'm not reclaiming screens as quickly as many others that do jobs. I coat and expose as I produce new designs. So, it can be hard to practice.

I found that the best method for ME is the glisten method. Using the thick edge of your coater, you coat the shirt side until the ink side shines like "glass", which for me is 3 passes. Then, you coat the ink side twice. 

What does a thicker stencil do? It leaves a thicker gasket for ink deposit IMHO. With a tighter mesh, I use pretty much all 180, I get a nice deposit on the first pass, then a flash, then a skim on a second pass, and depending on the design, maybe a third pass a skim coat, as I "build up" the print. It takes a little more time, but the end result for me is a very smooth print that can rival a water based print. I sell strictly retail and I am constantly complimented on quality of print, and I do some very inky designs. So hey it works...for ME!

Thicker stencil will increase exposure time. If I want to bust out a halftone, I may do a thinner stencil. But I don't mess with halftones a whole lot.


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## porkchopharry (Mar 4, 2012)

I should probably add that if I were doing black on white, I might do a thinner stencil. I love old school black on white prints. But...people want black shirts. So I rarely get to do one. I will toss one on the site now and then just to keep myself happy!


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## sben763 (May 17, 2009)

Andy have you ever tried just doing a 3/1. I only ever do a 1 on the ink side as you can shear the ink much better as you squeegee is closer to the mesh. On the ink side there is no need to make it glisten. 

Nikki, all info given by Andy is spot on and couldn't add much myself. With the Hi-Fi or the Saati Chem PHU you may find a 2/1 will produce the same results as the solids content is 46% for HI-FI and 50% for PHU. The PV if I remember right is 37%.


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## NFrancis (Oct 9, 2013)

sben763 said:


> After you have your exposure times dialed in. There is no need to adjust your exposure times for halftones, this will make it a greater chance to blow off halftones if you expose less time.
> 
> FREE Screen Printing Exposure Calculator here is a good exposure calculator and a good explanation on how to use. basically after you follow instructions which ever step gives you the best results is close to your target time. To further nail your time you can retest and use a narrower time like 5-10 sec. after you wash out go over you screen after it is dry with a magnifying glass or a loop and really look at you edges cause although it may look good from a foot away when looking up close choose the one with the smoothest lines as a jagged edge will indicate under cutting which is over exposure and common with your type of exposure unit but you can still do amazing work with that exposure unit as I had a similar unit for the first 6 years in screen printing


Ahh just found that same download a few hours ago, thanks for posting that link.

Good to know about my exposure unit.. I almost always see those jagged edges. I have two other partners who tend to dismiss it because the end result is usually acceptable if not unnoticeable, but I just can't handle that it's not perfect.

Although, like you mentioned about under cutting.. I may need to dial back my exposure. Looking forward to my step wedge results tomorrow.

Thanks again!
Nikki


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## NFrancis (Oct 9, 2013)

porkchopharry said:


> Hey Nikki,
> 
> Yep I use that method for all my prints. I'm going to be honest when I say that after 2 years I STILL struggle with screen coating at times. That's because I don't do print jobs. I do all my own stuff that I sell on my site and through retailers. So...I'm not reclaiming screens as quickly as many others that do jobs. I coat and expose as I produce new designs. So, it can be hard to practice.
> 
> ...


I may need to dabble around with a 2nd or 3rd coat. My prints are not consistently smooth, in fact that's my main issue right now. Fatigue and girl muscles may also play a roll in that outcome 

Thanks for the advice!! Much appreciated.

Nikki


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## porkchopharry (Mar 4, 2012)

sben763 said:


> Andy have you ever tried just doing a 3/1. I only ever do a 1 on the ink side as you can shear the ink much better as you squeegee is closer to the mesh. On the ink side there is no need to make it glisten.
> 
> Nikki, all info given by Andy is spot on and couldn't add much myself. With the Hi-Fi or the Saati Chem PHU you may find a 2/1 will produce the same results as the solids content is 46% for HI-FI and 50% for PHU. The PV if I remember right is 37%.



I'm going to try a 3/1 next time Sean. I read your notes on that in the hoodie thread. Makes sense.


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## sben763 (May 17, 2009)

Nikki you might try raising your self up 6"-12" when printing. This will allow you to use upper body weight and strength when printing. I have a YouTube video of me printing and I get the comments is doesn't look like I'm using much pressure. Well I am using some but a few advantages I have is I use all roller frames at 40+N. Use all ergo squeegees at the time of video I was using 70/90/70 but the developer talked me in to trying his 64A blade and it leave more ink at the same or less pressure.


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## NFrancis (Oct 9, 2013)

sben763 said:


> Nikki you might try raising your self up 6"-12" when printing. This will allow you to use upper body weight and strength when printing. I have a YouTube video of me printing and I get the comments is doesn't look like I'm using much pressure. Well I am using some but a few advantages I have is I use all roller frames at 40+N. Use all ergo squeegees at the time of video I was using 70/90/70 but the developer talked me in to trying his 64A blade and it leave more ink at the same or less pressure.


Sean, whats the name of your youtube video? Also, I've been eyeballing those roller frames.. watched a demo a few months ago.


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## sben763 (May 17, 2009)

NFrancis said:


> Sean, whats the name of your youtube video? Also, I've been eyeballing those roller frames.. watched a demo a few months ago.


Just search sben7633 and I have about 12-15 videos. All but that video labeled "print" were done for members sometimes they are done to show someone how to do with what they had and not necessarily the way I do it or I have found a better way by trial and error. There is a video of me coating screens with Ulano orange, Saati Chem PHU, and Ryonet HI-FI.


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## NFrancis (Oct 9, 2013)

Step Wedge Results - first try

I used an 10 step exposure calculator from Anthem and followed their directions.

- Ryonet HiFi Photopolymer Emulsion (new)
- EconoRed I Infrared Conveyor Dryer (older bulbs)
- Aluminum Pre stretched 110 mesh (first use - new)
- 1/1 coat ... humidity was around 50%


1st test was 45 second steps
2nd test was 33 second steps

Step 10 was the best row in each test but 33 seconds was best overall. I am wondering if I should test even lower second steps? I can't believe my exposure time is only 33 seconds. Still waiting for the Stouffer 21 Strip to arrive so I can confirm these results.


http://www.flickr.com/photos/[email protected]/11207724366/
http://www.flickr.com/photos/[email protected]/11207821793/


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## porkchopharry (Mar 4, 2012)

I had a 15 second exposure once with Textil PV on 180 (lowest mesh I use these days pretty much). It was a bad batch, or I accidentally exposed it in the shop. Only emulsion I had and I threw up a Hail Mary! It worked though!


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## sben763 (May 17, 2009)

Nikki did you do the test in steps? That time seems too fast. With a 25x36 exposure unit similar to your Vastex I was at 1:30-3:00 with the Ryonet Hi-Fi. Depending on thickness of stencil and mesh. I am making a step test sheet that has halftones, text, and spot color test and will be avalible in Black(for those only wanting to print with black) rich black(for those printing with colors) and 100% CMYK (for those with all black)


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## NFrancis (Oct 9, 2013)

sben763 said:


> Nikki did you do the test in steps?


I am skeptical too. 

I actually tested it twice.. 45 second steps and 35 second steps. Every 35 seconds I would move the sheet down a step leaving #10 exposed only 35 seconds and #1 for 350 seconds. Then once washed out I would leave in a sunny area for about 10 minutes.

Oddly enough, I have printed two jobs at an exposure time of 45 seconds on a 1/1 coat, 110 mesh with some nice prints. Just received the Stouffer 21 test today and will cross reference with those results.

Thanks for checking in!


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## sben763 (May 17, 2009)

Here is the Step test I made. They are only 3 step and are on a 13X19 each one is labeled all black or rich black and each zip contain 4 files with 35-65 LPI. The PDF has no halftones or LPI set for those who are using a RIP and wish to set that themselves. I recommend printing the pre-halftoned files in photo quality and paper setting premium photo glossy

The 100% shows some halftones and it may or may not print with some halftones. I noticed after I did this and has some dot gain control added that I forgot to remove. I will print the 55LPI all black and edit this post with results


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## NFrancis (Oct 9, 2013)

*Update*

Hey sben763 (sean) thanks for the Step test, they were a huge help. I've utilized them with some interesting results. I am still getting the best exposure with 45 - 55 seconds with 110 mesh, 1/1 coat, Ryonet HiFi and Vastex-I exposure unit. Even the Stouffer 21 Step guide washes out between 8-7 step.

If I go to 3:00 I am unable to washout sharp corners or detail. Pretty strange indeed.

Thanks again.
Nikki


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## WGiant (Oct 15, 2015)

sben763 said:


> FREE Screen Printing Exposure Calculator here is a good exposure calculator and a good explanation on how to use. basically after you follow instructions which ever step gives you the best results is close to your target time.


I realize this an old thread, but just wanted to say how helpful the step-test from Anthem is. Pre-made tests don't really make sense since they're not using the same printer ink and transparency film as we'll be using for all of our actual exposures. It makes way more sense to print our own and then everything will be dialed in with even our inks and films accounted for. Not that they should make a huge difference, but still worth keeping in mind.


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