Windows 10: How to set size of Paint canvas ?

I am inserting images into a Paint canvas but the size of the canvas changes. How do I lock the size. thank you !

:)

 

How do I customize the size of Paint 3D’s Canvas?

In Paint 3D, I can click "Canvas" icon,





then can drag the canvas' corner to change the size of the canvas.









Now I wanna each time while opening Paint 3D or using it, its canvas can have a fixed custom size of matching my mind.

How should I do?

Take Paint as an example to clearly explain further:

We know, we can easily customize the size of Paint’s Canvas, as for me, I can use Notepad to create a batch file named
ResetPaintView.bat, which reads as follows:

reg add "HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Applets\Paint\View" /f /v BMPWidth /t REG_DWORD /d 0x00000021

reg add "HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Applets\Paint\View" /f /v BMPHeight /t REG_DWORD /d 0x00000016

(Why is its size set to so small? because I frequently paste the screenshot to Paint, so need it become small enough.)

then save it.

Each time use it, right-click on it and then run it as administrator.

This is the way that customize the size of Paint’s Canvas.

Now I wanna that Paint 3D also can customize the size of its canvas just
simply as in Paint.

Please help me.

 

Changing the canvas size

I know how to change the canvas size, obviously. What I mean is that when I open Paint 3D the canvas size is a weird one, I can change it, but when I open the app again it's the same weird resolution, and it's getting pretty annoying to change it every
time. It's not a huge problem, but I'd like to know how to get 1920×1080 / 2048×2048 when I open the app.

 

Saving paintings with canvas color in Fresh Paint app

I have used canvas color feature on most of my paintings for changing the color of the background. Everything is fine except that I could not export my paintings with the canvas color changed. I have tried to dry the paintings or saving the paintings with
multiples types of files but none of them worked: all the paintings were exported with white canvas. Is there any possible way for me to save paintings with canvas color?

I am using Fresh Paint on a Surface device running Windows 10.

Thank you.