To make this junk journal page up you don’t need a pattern,
but I have created an instruction sheet for you to download for free if you are a beginner or like to see things in writing.

I have a VIDEO on how I made the vellum junk journal page here: vellum junk journal page idea (style one) 
this page looks fantastic and is so simple to create.
You can sew it to give it a decorative top stitch, or glue it if you don’t have a sewing machine.
Sewing paper pages is so easy using this idea