Hi, I mixed Javis Countryside scenic products scatter No 30 sand (Available on Ebay) with Humbrol enamel matt 155 until it was a thickish paste. I then stippled it on starting from the crown working down. After it was dry I rubbed off the loose bits with my hands and then added another four coats of 155 on its own. This smooths it out. Check out link 90th IDPG M1 Helmet Restoration
Phil
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