eliminate clear lines in the union of seamless textures

[Filo63]

I need a tip.

When I create repeatable, seamless textures, it is often necessary to rasterize them in png or jpg to make them usable for the printing departments of a client of mine who prints them on glass.

The problem is that, for antialiasing, a clear line remains between tile and tile. One thing that can be seen enlarging a lot, but unfortunately in printing, with ceramic inks, is very visible.

Is there any way to overcome this problem?

 

Thanks
Fabio

[MEB]

Hi Filo63,
If the tiles are all correctly pixel aligned, those lines (straight vertical/horizontal lines) should not be visible on canvas (at 100% zoom) neither on export. If you change the document's units to pixels, check each tile's X,Y coordinates and make sure they are all integer values (i'm assuming their width/height sizes are also integer values) you should be able to fix the issue.
To see the decimal parts of the X,Y coordinates in the Transform panel you may need to increase the number of Pixels to 3 (or more)  in the Decimal Places for Units Types section in Affinity Preferences, User Interface tab.

Other alternatives/paths you can take is to export the image to JPG or PNG at a higher resolution (say 8x or even 16x) then rescale the exported image down the same factor. It should get rid of the lines as well. 

If there's a common tile background colour, you may also try to add a larger square - filled with the same colour - encompassing all tiles and place it on the bottom of the layer stack to disguise these lines a little more.

[Filo63]

Unfortunately, the printer is disturbed by those lines that are seen with high zoom.

In the example, zoom 100-400-800%

Ciao
Fabio

[MEB]

Hi Filo63,
Did you pixel aligned the tiles as suggested? Any chance you can attach the affinity file for us to check please? I don't have access to a printer but will try to check the file and get it printed to see what's going on. Thanks.

[Filo63]

Ok, keep in mind that the customer uses large format printers, for glass, with ceramic inks https://www.tecglassdigital.com

https://www.dropbox.com/sh/9vhb4zcd0ezr7cc/AADtp0tFLpDACnGlfV5lvVaLa?dl=0

[MEB]

Hi Filo63,
The two larger image layers you have side by side on top (labelled 6) are not neither pixel aligned (X,Y coordinates are not integer values), neither have an integer width and height so they will never end correctly pixel aligned unless the original objects are re-adjusted so the resulting images originated from them have integer width and height pixel values.

The smaller two ones (the triangles) on the bottom right, do have integer width and height pixel values but are not pixel aligned (their X, Y coordinates are not integer values - see attached images below the marked area in the Transform panel). That's the reason the white lines keep appearing there. In the attached afpub file below this paragraph i've fixed the pixel alignment of the side by side images (triangles). They should now look correct at 100%, 200%, 400% etc and print correctly.

Sample.afpub

Note: to check if the images are pixel aligned (X,Y coordinates) and also have integer width and height values you must change temporarily the document units to pixels. Again, to see the decimal parts/values of the X,Y coordinates or the width and height values in the Transform panel you may need to increase the number of Pixels to 3 (or more) in the Decimal Places for Units Types section in Affinity Preferences, User Interface tab.

 

[Filo63]

Now it is clearer to me !!!

Thank you

[MEB]

You're welcome 😊