Mate window frames resizing

Hello All.
I am quite new Mate user, I like it.
I am asking how to make window frames wider.
Sometimes it is difficult to drag window bigger or smaller.
73s rami, oh6bi

Hi,
Basically thickness of windows borders are defined in themes.
However, you can change it by creating a customized version of used theme.
You can find themes at location /usr/share/themes/.
The best way to create your own version of a theme, that you copy entire contents of directory to your home, into /home/<your_username>/.themes/My_<Theme_Name>. You can see, I used a different name, adding "My_" prefix, to let me find it easily among themes in appearance settings window.

If copy is done, go to your new theme directory /home/<your_username>/.themes/My_<Theme_Name>/metacity-1.
Search the file "metacity-theme-1.xml". Open it with your preferred text editor.
Search sections started by "<frame geometry..."
In each of these sections there are items named <distance name="left_width...", <distance name="right_width...", <distance name="bottom_height...".
Values of these items define thickness of window borders. Change these numbers for desired thickness. You can play around a bit with different values until you find the best for your needs.
Good luck.