Underground Comix are known for using different prices, covers (art or color variations) and/or interior content to distinguish between printings.
1st print has 0.25 USD cover and is dated November 1967, but actually released in February 1968.
2nd print has 0.35 USD cover. Says 'Printed by Don Donahue' in blue on back cover. Subsequent printings have four additional pages not included in these original printings.
The Print Mint-
3rd print has 0.35 USD cover. No printer name on back cover.
4th print has 0.50 USD cover. 5th print has 0.60 USD cover. 6th print has 0.75 USD cover.
The Print Mint & Last Gasp-
7th print has 1.50 USD cover.
8th print has 2.50 USD cover. 9th print has 2.95 USD cover.
This issue has variants: