canvas-size | maximum size of an HTML canvas element | Canvas library

I have a TK treeview that has quite a few columns that I simply wish to put in a LabelFrame with a horizontal scrollbar. I have been through a ton of similar questions and nothing seems to be working. In each case, the tree extends off the edge of the window along with the scrollbar. I would like the displayed tree to fill the labelFrame, with a scrollbar at the bottom allowing the user to scroll left and right to view everything, and/or resize the window if their monitor is big enough. For clarity, I will say that I do not care how wide the table is, so long as the user can scroll left and right within either the default or a resized window.

I cannot put every permutation I've tried here, but this is a minimal example. I have tried with and without a canvas (though I believe I was doing that incorrectly), putting in a LabelFrame, pack_propagate(0), ordering the grid commands, etc.

I'm trying to make a section on a website have two background images that will reveal the bottom one as the pointer moves across the screen.

I'm still new to javascript, and my code is made up of bits and pieces that I've found on google, but I can't seem to get the top image to share the same resolution and image size for whatever reason as the bottom image.

Here is the link to my codepen: https://codepen.io/Awktopus/pen/zYwKOKO

And here is my code:

HTML:

I'm trying to export an image (PNG) which is larger than the maximum canvas size. I've tiled the canvas export, so that each tile is small enough to be generated (with toBlob). Now I need a way to merge the images together, but can't find a way that itself doesn't use a canvas. Is this possible somehow?

I want to make the dynamic ids like canvas1, canvas2, canvas3, etc. Here i binded id with {{cc}}