Gnome themes have moved into a trend of having a 1 pixel border on many themes. As themers create a version for XFCE's XFWM4, they often try to ensure the theme matches by making the XFCE theme border 1px, as well. This... is a mistake. Because the XFWM4 window manager uses that width to determine the Window Resize Grab Area.
I think that a 6px border is sufficient, though I personally prefer a 10px border.
For Zorin OS Lite users, I have taken the liberty of providing some XFWM4 Themes to match the default Zorin Themes, here.
These are already customized to have a larger grab area for window resizing.
Let's say you have your own theme that you want to customize the XFWM4 theme in order to increase the grab area.
Enter your theme directory and enter the XFWM4 folder. Here, you will find the Image Elements that build the Borders. (You may want to Copy the Theme and name it TEST-Theme in case anything goes horribly wrong in learning and experimenting with modifying it).
Here is a quick list of the common Border Images:
right-active right-inactive bottom-right-active bottom-right-inactive bottom-active bottom-inactive bottom-left-active bottom-left-inactive left-active left-inactive
top-right-active top-right-inactive top-left-active top-left-inactive title-1-active title-1-inactive title-2-active title-2-inactive title-3-active title-3-inactive title-4-active title-4-inactive title-5-active title-5-inactive
Let's start with
Open the image in GIMP. Hit the
5 key to zoom in. Go to the menubar and select
canvas size. This tells you what the size of the image is. You need this to be wider, so ensure that the Lock is unlocked for Width and Height so that only width is changed.
Increase the width to 6px (or 8px or 10px... whatever you want.) Click
Now, you will see a transparency background with the gap where the canvas is larger than the image.
You ned to Fill this in with your Window Background Color. The easiest way to do this is to take a screenshot of an Open Window, then open that screenshot in GIMP. Zoom in and copy One Pixel of that color, then
ctrl+left-shift+v to open that in a new tab or window. Go to the gimp menubar, then
Filters > Map > tile and enter in the width and height of The GAP that was left in the
right-active image opened in GIMP.
Copy it, paste it into that gap. Export it as the original file.
Minding your vertical and horizontal directions... Repeat this process for each of the above images.
Once all done, open your Window Manager Settings and apply to see how it looks. If you see any gaps or mistakes, it is pretty straight forward to see which image went wrong- and always be sure to check the active and inactive window.