@knot_bella then just take an old alpha of yours, use that to measure how wide a certain amount of knots is (for example how wide ten knots are) and use that to calculate how wide seventy knots will be (seven times the width you had for ten knots).
@knot_bella depends on technique and material used as well as your knotting tension, if you plan to knot this 🙂 If you've made an alpha pattern before, you can just measure how wide a certain amount of knots is and use that to calculate. If you've never made an alpha before, I don't recommend this as your first one 😉 it's a little big for that...