If you aren't familiar with Canvas parts in general, have a look at this guide first:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1148135377


Saving and using PNT files on the Canvas Glass parts:

- You have to navigate to your steam\common\ARK\ShooterGame\Saved\MyPaintings directory. If you can't see a MyPaintings folder you can either make the folder yourself or save a painting in the game so that it makes the directory. I recommend making a shortcut to this folder somewhere nicer (e.g. desktop)
- The file name has to be in the form paintingname_objectname
- The Canvas Glass parts were set up to use 256x256 images. Not sure what happens if you try other resolutions.

AS Canvas Glass PNT file name format (replace <Painting Name> with whatever you want):

Atlas Wood Canvas Glass Ceiling:
<Painting Name>_BP_AS_Atlas_Ceiling_Square_Wood_Glass_Canvas_C

Atlas Wood Canvas Glass Wall:
<Painting Name>_BP_AS_Atlas_Wall_Full_Wood_Glass_Canvas_C

Core Wood Canvas Glass Ceiling:
<Painting Name>_BP_AS_Core_Ceiling_Square_Wood_Glass_Canvas_C

Core Wood Canvas Glass Wall:
<Painting Name>_BP_AS_Core_Wall_Full_Wood_Glass_Canvas_C

Core Metal Canvas Glass Ceiling:
<Painting Name>_BP_AS_Core_Ceiling_Square_Metal_Glass_Canvas_C

Core Metal Canvas Glass Wall:
<Painting Name>_BP_AS_Core_Wall_Full_Metal_Glass_Canvas_C

If you want to use multiple images with the same name you need a number at the end for each file, like so:
<Painting Name>_BP_AS_Atlas_Ceiling_Square_Wood_Glass_Canvas_C
<Painting Name>_BP_AS_Atlas_Ceiling_Square_Wood_Glass_Canvas_C_1
<Painting Name>_BP_AS_Atlas_Ceiling_Square_Wood_Glass_Canvas_C_2