Why is the result noisy? :(

[reza34963173n4uo]

My problem is that I do all the steps to make a png image, but when I see the final image on the redbubble site, the image has noise.



I will explain the steps I took in the picture.



1- I made the image in Illustrator:

2- I saved this method:

4- Output result in pc (png format):

So far everything is normal

But My problem started from here:
I upload the image on the Redbubble site, when I open the uploaded image on the Redbubble site in a new page, there is noise on the image.

Now my question is:
First: Is this my method to save a png file correct?
Second: If my method is correct and normal, do you think the problem is from the RedBubble site? Is this a bug for the RedBubble site?
Because this noise is not seen in my system

[Monika Gause]

Did you apply a pattern?

[reza34963173n4uo]

Yes, I followed your method in making the pattern and everything is ok and normal

[reza34963173n4uo]

Oh, I forgot to say that ,the mode is  " CMYK" 

[Monika Gause]

CMYK doesn't make a difference with this. The problem happens with patterns. Those are the pattern bounds. And this often happens with patterns under a lot of conditions and then some more.

I would just open the PNG in Photoshop and paint over these 2 places (it's in the yellow as well) and also check for semi transparent pixels along the borders. That should be the easiest solution in this cse contrary to figuring out different rendering methods for the pattern or changing the resolution or whatever else.

[reza34963173n4uo]

[Monika Gause]

You have to make sure that artboards are aligned to the pixel grid. The corners need to be on even pixel positions, no comma values in there.

Then export at multiples of 72 ppi as the resolution. But still you might get seams inside.

[reza34963173n4uo]

I get the best result when I save the image to the EPS in illustrator and then save it to the PNG again in Photoshop, the result is this:



The result is great, but the way is a little time-consuming 😞

[Monika Gause]

Can you instead directly open the AI file in Photoshop? That could save you one step.