Mix Rusty Powder with Powertex or Easy Structure, add a dash vinegar and water to the mix then spread with a pallet knife or brush. You can also try mixing Powertex with 3DSand, Rusty Powder and a dash of vinegar, this results to a coarser paste and a rough rust effect. For best results, spray your artwork with a mix of 50% water and vinegar a few times, allowing to dry in between. Note the full effect takes 24 hours to activate, if you use too much vinegar you will get a very dark colour and lose the beautiful orange and red rust effects. With more than FOUR times the amount of product than the small size, this is the recommended size if you know you are going to LOVE playing with Rust Effects!