My First Zimmerit How Hard Can It Be

I m trying to make a handmade Zimmerit from different putties. Which technique works the best Zimmerit was an antimagnetic paste applied to German tanks during WW2. It had a specific texture with almost a dozen different patterns. This coat was applied in a factory by hand and as such, it wasn t perfect. This makes it quite tricky to replicate on our scale models. I believe it must be thin enough to look in scale but at the same time it must have volume so the pattern is clearly visible. There are many