The program requires an even number of tiles in both axes
To edit the knot, toggle the barriers to be visible, then tap/click on the middle of a line to toggle the barrier (it will turn red) - the knot will automatically respond unless an error occurs
If the barriers result in an error, keep adjusting until the error is resolved
Tap/click the center of a tile to hide that tile. This can allow you to block out areas of the knot (once they are 'boxed in' with barriers) or create a perimeter, for example
Press reset knot to remove all barriers and to update based on the input values
The relationship between line width, pixels per tile and outline width is buggy (sorry!). Try to make them multiples of 3
You can create massive knots, but the program will significantly slow down! The entire knot is recomputed every time a barrier is added/removed.
To save, press-hold/right-click and Save Image As...