Prime with meal after mixing in 5% dextrin and 3% barium carbonate to neutralize any sulfur acid that might be present. This star uses water for binding and priming. The hybrid combination of Perchlorate and Chlorate oxidizers makes this formula safer than if it was all chlorate. It is not at all sensitive to impact or friction but is heat sensitive and speeds up the burn rate allowing for normal star sizing. 3/8″ stars burn 3 seconds and 1/2″ stars burn 3.5 seconds. There is low ash residue too. Color: This blue is very pleasing and a deep blue making it suitable for the name “Royal Blue”. You will not be disappointed. I came up with this formula after being disappointed with so many other formulas, including my own old blue formula. This is the blue I will be using from now on. It should make a fine purple by changing the copper carbonate to 5 and adding 5 strontium carbonate to keep the total of the two carbonates to 10. Adjust the color toward blue or red by upping or lowering each carbonate to get the proper purple color and while keeping the total of the two carbonates at 10 parts.