Hi Barbara

If you have a 5"x7" reference picture and use a half inch grid and want to enlarge to 16"x20" canvas :

Place the grid onto the reference picture. You will then have a picture divided up into 10 squares left to right and 14 squares top to bottom.

You now need to divide your canvas up into 10 squares left to right and 14 squares top to bottom.

Let's start with the left to right 10 squares.

Place your ruler or the canvas left to right

count 10 squares, one square every half inch (the size of your grid on the reference picture) You will see that by the time you get to 10 you are not all the way across the canvas yet. This tells you your canvas is bigger than the reference so we need to enlarge the size of the squares - I know it sounds obvious, but bear with me.

Now we will double the size of the squares - one inch squares.

Start counting along the ruler again, but this time count is one inch intervals. When you get to 10 (the amount of squares you need), take a look if you are inside the canvas, on the edge or off the canvas.

If you are still inside the canvas, then your blocks need to be even bigger, so make your blocks 3 times as large (one and a half inches) and start counting again. Continue enlarging your squares until when you count the amount of squares you need and you are either on the edge of the canvas or OFF the edge of the canvas.

If you are on the edge of the canvas you are in luck. Simply mark off your squares in the same interval, eg. if you were counting every one inch, then mark off every one inch. If you were counting every one and a half inch, then mark off every one and a half inch.

If however you are OFF the canvas, then hold the zero end of the ruler against the side of the canvas to form a pivot point. Then rotate the ruler around this pivot point until your 10 square mark touches the opposite end of the canvas. Lets say you were measuring your 10 blocks every one inch, then rotate the ruler until the 10 inch measurement touches the opposite end of the canvas.

You have now basically "squashed" your ruler to fit the canvas. You can see me doing this in the tutorial video

HEREYou can now mark off your intervals (in the example every one inch).

You have now split the canvas into 10 blocks.

Extend these marks all the way down the canvas.

Use the paper transfer method I show in the tutorial video to "copy and paste" the lines top to bottom as well - No need to go through the process again as the blocks are square.

and there you have a perfectly fitting grid