This pattern were stitched on 28 count "sand" evenweave. The biscornu pattern is 68x68 stitches (stitching over 2 over 2), making it 5"x5" before biscornu construction.
This is an advanced beginner/intermediate level pattern - the pattern includes using partial stitches and constructing the biscornu. I advise to use a high count fabric rather than aida, although it could be done on aida.
This listing is for a digital pattern only. There are 2 pdf files to download. One files include the pattern depicted with symbols on color. The other file includes some pattern specific instructions, including instructions on how to construct your biscornu with pictures, and also a picture of the finished pattern. Please be sure to download both files.