Depending on what you mean, would this work?
1) Take two identical pieces of paper.
2) Cut one into horizontal strips about one inch tall
3) Cut the other into vertical strips about one inch wide
4) Weave the two sets of strips together – I hope it’s obvious how this is supposed to be woven together when finished, since I can’t draw pictures here.
5) Draw/write your message on the woven result
6) Separate the strips

The result will be a bunch of strips that are alternately squares of stuff and blank squares. The strips need to be put back together in the right order to get the whole message.