An electrostatic ink composition, wherein the composition is formable by combining: chargeable particles comprising a resin comprising a polymer having acidic side groups, and a cyclic anhydride, wherein the composition further comprises a carrier liquid and the chargeable particles comprising the resin comprising the polymer having acidic side groups are dispersed in the liquid carrier, wherein the liquid carrier comprises a hydrocarbon, a silicon oil or a vegetable oil; and wherein the cyclic anhydride comprises a molecule of formula wherein - - is a group selected from wherein R 1 and R 2 either together form an optionally substituted ring or are each independently selected from a group selected from hydrogen, halogen, optionally substituted alkyl, nitro, cyano, hydroxy, optionally substituted alkoxy, optionally substituted amino, carboxy, alkoxycarbonyl, optionally substituted alkylcarbonyloxy, optionally substituted arylalkoxy, optionally substituted acyl, and optionally substituted aminocarbonyl; R 3 and R 4 either together form an optionally substituted ring or are each independently selected from a group selected from hydrogen, halogen, alkyl, nitro, cyano, hydroxy, optionally substituted alkoxy, optionally substituted amino, carboxy, alkoxycarbonyl, optionally substituted alkylcarbonyloxy, optionally substituted arylalkoxy, optionally substituted acyl, and optionally substituted aminocarbonyl; -X- is selected from -O- and -CR 11 R 12 -, wherein R 11 and R 12 are each independently selected from a group selected from hydrogen, halogen, optionally substituted alkyl, nitro, cyano, hydroxy, optionally substituted alkoxy, optionally substituted amino, carboxy, alkoxycarbonyl, optionally substituted alkylcarbonyloxy, optionally substituted arylalkoxy, optionally substituted acyl, and optionally substituted aminocarbonyl; R 5, R 6, R 7, R 8, R 9, R 10 are each independently selected from a group selected from hydrogen, halogen, optionally substituted alkyl, nitro, cyano, hydroxy, optionally substituted alkoxy, optionally substituted amino, carboxy, alkoxycarbonyl, optionally substituted alkylcarbonyloxy, optionally substituted arylalkoxy, optionally substituted acyl, and optionally substituted aminocarbonyl, or optionally at least two of R 5, R 6, R 7, R 8, R 9, R 10 together form a ring, and the ring may be selected from an anhydride-containing ring, an optionally substituted alkyl ring, an optionally substituted aryl ring, and an optionally substituted heteroaryl ring. chargeable particles comprising a resin comprising a polymer having acidic side groups, and a cyclic anhydride, R 1 and R 2 either together form an optionally substituted ring or are each independently selected from a group selected from hydrogen, halogen, optionally substituted alkyl, nitro, cyano, hydroxy, optionally substituted alkoxy, optionally substituted amino, carboxy, alkoxycarbonyl, optionally substituted alkylcarbonyloxy, optionally substituted arylalkoxy, optionally substituted acyl, and optionally substituted aminocarbonyl; R 3 and R 4 either together form an optionally substituted ring or are each independently selected from a group selected from hydrogen, halogen, alkyl, nitro, cyano, hydroxy, optionally substituted alkoxy, optionally substituted amino, carboxy, alkoxycarbonyl, optionally substituted alkylcarbonyloxy, optionally substituted arylalkoxy, optionally substituted acyl, and optionally substituted aminocarbonyl; -X- is selected from -O- and -CR 11 R 12 -, wherein R 11 and R 12 are each independently selected from a group selected from hydrogen, halogen, optionally substituted alkyl, nitro, cyano, hydroxy, optionally substituted alkoxy, optionally substituted amino, carboxy, alkoxycarbonyl, optionally substituted alkylcarbonyloxy, optionally substituted arylalkoxy, optionally substituted acyl, and optionally substituted aminocarbonyl; R 5, R 6, R 7, R 8, R 9, R 10 are each independently selected from a group selected from hydrogen, halogen, optionally substituted alkyl, nitro, cyano, hydroxy, optionally substituted alkoxy, optionally substituted amino, carboxy, alkoxycarbonyl, optionally substituted alkylcarbonyloxy, optionally substituted arylalkoxy, optionally substituted acyl, and optionally substituted aminocarbonyl, or optionally at least two of R 5, R 6, R 7, R 8, R 9, R 10 together form a ring, and the ring may be selected from an anhydride-containing ring, an optionally substituted alkyl ring, an optionally substituted aryl ring, and an optionally substituted heteroaryl ring.