Part of my selection that I made with the magic wand tool is only visible at a 400% magnification

[dehskins]

I am embedding a drawing into my file and removing the parts I don't want. It is a simple drawing. I have used threshold on it, so it is solid black and white. I select all of the black and delete the parts I don't want. While it appears that I have deleted all the excess it keeps reselecting parts that are otherwise invisible. After several attempts, it appears as though as though I have isolated the part of the drawing I want. I select the black with the magic wand tool and it shows only the area I want to keep until I zoom into the screen tremendously close only to see more marching that were invisible and not showing up the same way as the other marching ants. That makes for pretty unproductive editing. It is not difficult to have invisible selections with the Affinity apps. It happens all the time. This is the first time I have seen part visible and part invisible.

[Old Bruce]

Do you have a Feather setting that is not 0% for the "magic wand" tool?

[NotMyFault]

On 12/18/2023 at 1:11 AM, dehskins said:

I am embedding a drawing into my file and removing the parts I don't want. It is a simple drawing. I have used threshold on it, so it is solid black and white. I select all of the black and delete the parts I don't want. While it appears that I have deleted all the excess it keeps reselecting parts that are otherwise invisible. After several attempts, it appears as though as though I have isolated the part of the drawing I want. I select the black with the magic wand tool and it shows only the area I want to keep until I zoom into the screen tremendously close only to see more marching that were invisible and not showing up the same way as the other marching ants. That makes for pretty unproductive editing. It is not difficult to have invisible selections with the Affinity apps. It happens all the time. This is the first time I have seen part visible and part invisible.

Do you really work on the embedded document?
I suggest to rasterize and trim any embedded (placed) files once after you have placed it and put it into the wanted size and position to ensure they have the exact same DPI as the parent document. 
 

Or make a copy of the embedded document, and do the masking there, so you can import the wanted parts directly.

Background: you may have a DPI mismatch between selection (which normally uses document DPI) and layer DPI (which could be higher or lower). This combination gives very confusing results and should be avoided.

[dehskins]

It does work better working with a rasterized image. My issue is the visibility of the marching ants—just one of those things.

[Lee D]

@dehskins In terms of the visibility of the marching ants, I can't seem to replicate the issue with any selections I'm making.

Can you do a full screen recording that shows you making the initial selection and then zooming in?
A copy of the file used may also be helpful.

[dehskins]

I have abandoned the project I was working on. There is no file to share.