lines around JPEG file images

[Addlet]

Can someone please tell me why I am getting lines around the edges of JPEG file images when they are exported as a PDF or even if I use them on a web page after editing them in Affinity Photo I seem to get these lines around the edge?
I thought it was because I may have had image border selected in FX, but that is not the case.

I tried going around the edge of the image with the erase tool just in case but that does not seem to fix it, as you can see in the image of the hand holding a feather there is a faint line around where you can see that I have tried to erase the key line. You can also see this in the image of the ships wheel a little bit too.

Thanks in advance for help with this.

test pdf.pdf

[GarryP]

Welcome to the forums @Addlet

Without access to the original document it’s difficult to tell immediately what the cause of this could be.
There could have been some problem with pixel selections, or it could be a pixel-alignment problem, or a blend mode/options issue, or various other things.
Would it be possible for you to attach one of the problem images so we can look at it in isolation?

[Gnobelix]

Hello @Addlet,

Welcome to the forum.
I suspect that your JPG files have been placed,
and are now image files that are not editable in Photo.
The placed files must be rasterised so that they are editable.
I hope this helps

Cheers

test-2 pdf.pdf

[lacerto]

This is a question of having partially and fully transparent areas in all or most of the images involved. There might be some clever way to get transparencies properly filled (flattened to white), but one sure method is to group all images, rasterize the group and then use Select > Alpha Range > Select Fully Transparent, and fill with pure white, and then Select > Alpha Range > Select Partially Transparent and fill with pure white.