gaussian blur and gradients are not smooth.

[romaz2]

Hi

in affinty designer 2.2.1 i have noticed a bad quality unsmooth gradient and gaussian blur, i dont know why, but the dithering gradient option is enabled, and it its more bad whend it is disabled, adding some noise to the color can smoothen it a little bit but not resolving the problem.

help please,

thanks 

this is the gaussian blur 

and this is the gradient 

 

[romaz2]

i even see this on pixel brush, please see the black strokes of the soft edge pixel brush it is banding 

please help 

[Dan C]

Hi @romaz2,

Gradient banding can occur in 8bit colour documents, due to the limited colour space. This has been previously covered in the below posts on the Forums - 

I hope this clears things up.

[NotMyFault]

For the sake of completeness I just want to add that even with RGB/16 document format Affinity is unable to render smooth gradients, as rendering on screen is capped at 8 bit.

Exported documents are not impacted. Affects all versions V1 and V2.

 

[romaz2]

thanks for your answer, i understand that for gradients. i will try to apply some noise, but why it is also so bad on pixel brushes, please see the one on my first comment, i also tried spray brushes and the also have some banding, i dont think that i have this a month ago 

[NotMyFault]

It depends on what color profile is used. A wide gamut profile will make this wort, as the steps between color values become larger.

So for smooth results use RGB/16 and sRGB, and add noise or a little dissolve filter on top (from Photo). When bound to Designer, You may add a 50% gray rectangle on top with some color noise in blend mode linear light

[romaz2]

i am using a cmyk color profile because it is for printing, 

is there any other way to solve this without noise, because i need to add a lot of noise to fix this

also does dithered gradient option affect the exported image ?

[loukash]

13 minutes ago, romaz2 said:

i am using a cmyk color profile because it is for printing

Then what you see on your display is only an approximation anyway.
You may want to use rich black to reduce banding in print, however be careful with it. The sum of all four inks shouldn't exceed 300% by much, otherwise the printer won't be happy about it.

[loukash]

Here an old article from the top of my quick search results that deals with this issue:
https://haizdesign.com/graphic-design-2/cmyk-gradients-in-indesign

[romaz2]

thanks, i tried what you wrote in the article, but it doesn't make it any better at the end i need to use high amounts of noise.

 

[loukash]

33 minutes ago, romaz2 said:

but it doesn't make it any better

Again, what you see in your display is just an approximation of what you're gonna print. CMYK ≠ RGB
That said, there are still a few unresolved bugs with 100K overprint and transparency effects like blur or drop shadows.
For example in this thread I was exploring some of these issues: 

How are you going to print it anyway? Digital? Offset?

[romaz2]

i am outsourcing the printing to a company who use DTG printing. they request Png files without overly bright colors  

[loukash]

3 hours ago, romaz2 said:

they request Png files

PNG?! Are you sure?
PNG doesn't support CMYK.

[thomaso]

Quote

DTG printing

2 hours ago, loukash said:

PNG doesn't support CMYK.

"DTG printing" seems to prefer RGB data and to convert CMYK to RGB:

Farbraum – Die Druckfarben werden automatisch aus dem CMYK- und Weiß-Farbraum gemischt. Für die Erstellung einer Druckdatei ist es häufig erforderlich, die Farben im RGB-Farbraum anzulegen. Zwar übernehmen Konvertierungssoftwares von Druckmaschinen eine Separation der Farben in CMYK- und White-Kanäle vor. Allerdings werden in CMYK angelegte Druckdateien automatisch in RGB konvertiert, wodurch es zu Farbabweichungen kommen kann.

Color space – The printing colors are automatically mixed from the CMYK and white color spaces. To create a print file, it is often necessary to create the colors in the RGB color space. Printing machine conversion software separates the colors into CMYK and white channels. However, print files created in CMYK are automatically converted to RGB, which can lead to color deviations.

(sorry, I found the colour space info in German only) https://helpcenter.shirtigo.de/wiki/druckverfahren/digitaler-textildruck-dtg/#Drucktinten

[NotMyFault]

So the printer wants an PNG file in RGB / sRGB which he then converts on his own into CMYK (probably the print device).

And you should use only a subset of RGB colors compatible with the unknown CMYK profile of the printer.
Sounds like fun. I would not care about banding (unless proven wrong), it will be probably the smallest problem.