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Halftone Blur Issue

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Ok so not sure if this is a bug... (feel free to move where necessary)

I noticed an issue when using the halftone filter and this is regardless of the settings used (in my case I want maximum contrast), when applying a halftone filter to a layer that has been threshold at 99% (thus creating essentially  1-bit raster ie: Black and White pixels) and rasterized (or nesting the layer within a group and applying the halftone to the group), the halftone filter creates what is essentially a blurred halftoned edge.

In Photoshop when we are trying to "RIP" halftones at high resolutions for output to film transparencies, we need to halftone our separated plates, usually a greyscale image. During this process we will have "objects" or portions of the image that are solid black and white pixels, no grey edges, to be halftoned like for instance a piece of solid text in which we do not want a "fuzzy" edge. During that process in Photoshop it's bitmap halftone feature will not "add" a blur to the edges of pure black and white areas of the image whereas Affinity's filter does.

I would love for the ability to RIP in Affinity and this cannot be done successfully without this issue being "corrected".

Here's a quick scenario that you can test with:

  • Create a new document (300 dpi preferably)
  • Create a pure white fill layer
  • Create a vector rectangle that is pure black
  • Add a Threshold adjustment layer above both previous, set to 99%
  • Group all three together -or- raster all three
  • Apply a monochrome halftone with contrast set to 100%

Take notice that the edges of the rectangle will now have a halftone applied to them. This does not happen in Photoshop's bitmap halftone. How could we remedy this "issue" or add to the feature set in Affinity for those of us in the screen printing community that desperately would like an Adobe alternative. 

Attached are two images, the rasterized then threshold'd image that is basically a 1-bit image ( obviously to post on the board it is saved and compress so the edge is fuzzy), and the resulting fuzzy edge halftoned version of the same image. 




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Hey Sullyman,

First of all, I do not claim to be a master of halftone screen printing so you may have to educate me here :) 

If I do what you said but without grouping, this doesn't happen—why is grouping important? I used a Round Dot Type instead of a Cosine one—does that matter? PS uses a round one... If I don't group, the dots appear inside the shape.

The process in PS feels completely different to the steps you told me to do in Affinity Photo so is it fair to expect different results?

What happens if you just use a regular image with a Halftone Filter and a Threshold Adjustment? I'm getting pretty similar results in PS and Photo if I use a Round Dot Type.


Photo does appear to be slightly blurrier so is this the point you're trying to make?


When I was screenprinting at college using PS, we just used to convert to greyscale and then convert to bitmap w/ halftone round and print. In Affinity, I'd just apply a Halftone filter to my image and print that, so I can't understand all the need for the fill layer, threshold (as this blows out detail for me) and the group.

We then just used a RIP to make a profile for Illustrator which was even better as it retained the sharp text.

I'm just trying to understand all this so I can go and ask the right questions!


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  • 2 weeks later...

No problem @Chris B, I appreciate you throwing your hat in the ring!

Ok so first, the reason why I group is; to achieve halftones I need to have a white background layer (usually a white fill layer) which allows me to halftone the black/greyscale objects that I have as the artwork. Without the white background for the halftone filter to use, you will receive no halftones from the filter.

You cannot create successful halftones for screen printing without this method because you'll land with results like your second example, on the right side version. This would not work because a "gradient transparency-ed" edge cannot be printed onto screens. We need solid black dots with no gradient fading as I'm sure your aware of.

The point of this entire effort is to be able to take advantage of Affinity's ability to "Live Halftone" which would be an amazing feat for the screen printing industry. Affinity really has something going here! It would be nice to make edits to the art while the halftones are live thus my grouping workaround to get them working. (Now if we could only have a "rasterize filter" that would essentially let a group of layers have a filter applied to them that non-destructively applies a flatten/raterized property to a group without losing their editability (and not using "smart" objects like Photoshop... but that a whole other can of worms.)

In my example you'll notice that I have a live vector object that is using my work around to allow for the halftone filter to work, but I get a "fuzzy/blurred" halftoned edge to the vector shape that has none. This is the issue I'm trying to point out and happens to text objects as well. Photoshop has next-to-none of this when going through the steps you mentioned above.

I'd like for Affinity to fix what is possible in this area as what is so seemingly such a small issue but is actually a very big one for the screen printing industry. Halftones and their angle and size are absolutely critical to successful prints. Again, all of us in the industry would love an option to get away from Adobe were we can. 

Lastly, will we see the ability to get .25, .5, .75 increments for our angles?  The industry standard is 22.5, 67.5, this would a very welcomed addition to the filter.





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Right, I see what you mean. I think I need to pull this apart and get something over to dev, then.

I'm pretty sure we allow floating points. The app rounds up in the dialog when you type it in, however you should see a visual difference. If you take a screenshot after typing in 22.5 and then take a screenshot after typing in 23, you should see what I mean. This is something we should probably also look at.

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  • 10 months later...
  • 7 months later...

Happy to see this topic has been discussed before. Hoping my input will help the issue noted be adressed...

I was also looking for a way to output film for screen printing without Photoshop. I was overcome with joy when I realised Photo had an halftone live filter. But in effect, the halftone filter does seems to add some sort of blur. Mind, I did not attempt to screenprint with it yet, but looking at the halftons output from Photo, some details seem lost or blurred,  as compared to one done in Photoshop or Gimp. Photo’s filter also adds a dotted line around the output. 

I join a file with the halftone output of 3 of the 4 ways I found to output halftone so far. With Gimp, that has a filter that creates halftone, Affinity Photo and the live halftone filter, and Photoshop with it’s bitmap image mode. The image is 25 cm high, and the halftone is 40 lpi or equivalent (as far as I could tell, only photoshop offers an actual LPI setting). All halftone were created from the same grayscale image, witch is a seperation of the K component of the original image I did in Photo and exported as a.tiff.

 Apart from some visible differences in density and contrast between the renders from the 3 programs, I outlined some areas with red circles where I see the blurring of details occuring. 

On a last note, I will test print in CMYK the 3 halftoning methods for that same image and report back...Demo-Halftone.thumb.jpg.0405db6b82a77a5d1749366146c090df.jpg

Edited by marteau
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Hey marteau,

Thanks for your contribution. 

I would also make sure you're viewing the document at 100% as Live Filters will adjust the view to the zoom level. In theory, printing a destructive halftone and a live halftone should produce similar results so don't get fooled by the view. We always recommend viewing the doc at 100% before print and export.

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Thank's Chris

It makes sense that the filter adjusts according to zoom level when viewed from Photo, but please note that the accompanying image I posted is a Photo .tiff output of a .tiff file opened in Photo and  live halftone filter applied. No resampling occured. Original file is 25 cm height at 1000 ppi. Output .tiff is the same. Comparing the 3 outputs from Gimp, Photo and Photoshop, size kept the same in all situations, with the same original grayscale .tiff, it's fairly easy to see there is a sort of blur in the Photo output compared to the other. I outlined some of those that seem illustrative to me with red circles. 

Mind you that I do understand that the Photo filter was probably not intended to create screen printing output, but probably more as a graphic effect filter, 

Also mind you, I really like the way the Photo halftone filter handles the intensity and contrast from the original grayscale. Much closer to what I would expect. Gimp, in comparison, preserve the details well, but significantly darkens the output, as if I would need to apply some curves to the original before applying the halftone filter. 

Lastly, also mind you that the comparative blur of the Photo halftone filter is apparent all the way from the computer screen to the revealed screenprinting screen. I still have to print a full cmyk test of all 3 halftoning method. I intend to create the 3 images on a same screen from the 3 halftoning methods and do a test print of it. I just reclaimed 4 screens this morning for the purpose of that test. 


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Thanks! I figured it was a screenshot of all the apps together—I've just read it again and see you mentioned the tiff export.

So there's no difference between 100% view that I can see with live and destructive in our app but there's a clear difference between the output between the three apps. I'm not sure if it was intended for screen printing or not but if that's part of the process then it might be worth us looking at improving it.

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Yeah... I guess that you looking into it is kind of Sullyman's and my hope.

Wether the filter was intended solely for graphic effect or not, it is certainly to the user's advantage that it does both provide a nice graphic effet and also a way to reliably "live" halftone a piece for more rare outputs methods sush as screen printing. Obviously there are much more pieces to the puzzle of preparing a graphic for screen printing, but most of the other ones, at least for CMYK printing, such as separations, color management and adjustments, are readily feasible and reliable in affinity. 

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Ok... reporting back on my print test of Affinity's halftoning. I created a CMYK separation of the original file from Affinity from witch I obtained 4 grayscale .tiff files for C,M,Y and K. Files were 20 cm high at 1000 ppi. From theses files I obtained halftone renderings for film positive from Affinity and Photoshop, with the classical halftone screen angles for each color : c : 15 degrees, m : 75 degrees, y : 0 degrees and k : 45 degrees. Since I had space on the screen, I also created a third series of halftone files with Photoshop to test something else I read about once : using 22.5 degrees for all halftone screens.

I am posting photos of the result. Keep in mind that it is a fairly small image (20 cm high) for a 40 lpi print, and I am still quite new to printing CMYK and colors are not that good. I am still adjusting my inks, stroke etc. Halftone was set to oval 40 lpi in photoshop, and cosinus 25 dot size in Affinity (I assumed that 1000 ppi devided by 25 dot size giving 40, it must be a good approximation of Photoshop's 40 lpi) It is fairly easy to see that the print from the Affinity halftone has a subtle blur over all and in fine details. It was also much harder to reveal the Affinity halftone's fine dots in screen than the Photoshop halftone, as if the smallest dots from Affinity at 25 dot size are smaller then Photoshop's smallest dots at 40 lpi. One thing to note regarding that last point : Photodhop's dots are oval while Affinity's are round; maybe this explains that. 

Also, the Affinity halftone seems a little less intense, or dense, than the Photoshop one, on print and looking directly at the film positive.

Lastly, but unrelated to the Affinity halftone question, having all CMYK halftone screen angles set to 22,5 degrees did give a cleaner result with no moire or other banding effect to the print. There is actually more patterns and banding with the print from the Photoshop halftone with c : 15 degrees, m : 75 degrees, y : 0 degrees and k : 45 degrees angles

So here is me still hoping the Affinity team will spare some time making the Halftone filter adequate for screen printing. To that effect, I would suggest : lpi instead of dot size, oval cosinus dots, the possibility to have integer in screen angles (22,5...) .


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