connect the dots grid system

[taintedplay]

I have a jpeg that I am wanting to paint on a 12x15ft canvas. I was thinking of doing like a grid system with 4 inch spaces between lines, and finding the distance from the lines on the jpeg to the edges of the canvas and then connect the dots.

 

IE a dot 48 inch from top, 108 from left side which connects to a dot 4 inches down (size of grid) until i have an outline.

 

Is there an easier way to do this?

[ReMark]

Project the image onto the canvas and trace the outline or buy a large pantograph and trace the outline. You probably don't know what a pantograph is.

[taintedplay]

i somehow didnt even think of a projector. That would be a ton easier, thanks for the idea

[BIGAL]

Plot multiple sheets tape to rear of canvas and backlight or like Remark project image on rear not front.