Knitter's graph paper is proportional, rather than providing the same numbers of squares per inch for both stitches and rows. This means if the ratio is 5 stitches per inch and 7 rows per inch, the proportion is reflected in the size of the graph paper boxes. They end up as rectangles rather than squares.
This type of graph paper was used in the past when knitting Intarsia but at the moment picture knitting isn't as popular as it once was.
I use the graph paper when I'm designing. It's a quick way to lay out angles and curves. In many cases you get a more accurate shaping due to the constant rounding off when working mathematically. You can see lots of examples in my Design-a-long series which starts here.
You can print this paper off here or just google other sources.
I've included some photos below that came from one of my very early design classes.
|This is what happens when you draw a shape on regular graph paper and knit it, the shape gets squashed down.|
|This is what happens when you draw a shape on knitter's graph paper and knit it, the shape maintains it's proportions.|