Rob Smith's Silicone Flow Blood Arterial - Venous - Aged 40ml Robert Smith Blood £5.99 Silicone Flow Blood 40ml: [Choose]ArterialVenousAged Quantity: at £5.99 each Add To Basket 4 in stock. Silicone Flow Blood is mouth safe and washable but has extra flow properties. It will run like real blood and not bead on silicone props/appliances and direct applied effects. Available in 3 shades Artierial (Light) Venous (Dark) Aged Silicone Flow Blood is Sorbitol based and was developed to flow naturally on silicone props. It is very free flowing on skin and smudges very thinly.