This is a FREE downloadable PDF file for weathering engines using AK Interactive's Fuel Stains Weathering Set.
You don't have to buy anything to download this file, but you still have to go through the checkout procedure. Just add this to your cart and checkout.
The free PDF file consists of a 'How To: Product Use' page by AK Interactive. There are more located at their website, but this page pertains to this particular weathering set (use link above).
FREE downloadable PDF file.
Watch for download link after checkout or, if you are registered on the website, go to your account and look at your order.