(PHP 4 >= 4.0.6, PHP 5, PHP 7)
Set the thickness for line drawing
bool imagesetthickness ( resource $image, int $thickness )
imagesetthickness() sets the thickness of the lines drawn when drawing rectangles, polygons, ellipses etc. etc. to thickness pixels.
Parameters:
image
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor