Abstract: Disclosed is a novel photosensitive composition comprising an alkali-soluble photosensitive resin and an additive consisting of at least one aromatic polybasic carboxylic cellulose ether ester which is a reaction product of an aromatic polybasic carboxylic anhydride with a cellulose ether compound of the formula (I) or (II):R.sub.a.sup.1 R.sub.b.sup.2 A (I)orR.sub.c.sup.3 R.sub.d.sup.4 R.sub.e.sup.5 A (II)wherein R.sup.1 represents a hydroxyalkyl radical having 3 or 4 carbon atoms; R.sup.2 and R.sup.5 are a hydrogen atom or an alkyl radical having 1 or 2 carbon atoms, respectively; R.sup.3 and R.sup.4 represent a hydroxyalkyl radical having 2 to 4 carbon atoms, respectively, and are different from each other; A represents a cellulose residue, and; a, b, c, d and e, respectively, represent a positive number.

Abstract: Disclosed is an alkali-soluble photosensitive composition having an excellent stability in photosensitivity and developing property over a long storage time and a high ink-sensitivity. The composition comprises an aromatic azido compound and a novolak resin prepared by condensation polymerizing, in the presence of an acid catalyst, formaldehyde, a phenol compound of the following formula (I) and another phenol compound or compounds of the following formula (II) and/or formula (III). ##STR1## wherein, R.sub.1 =H or -CH.sub.3, R.sub.2 =alkyl of 3-15 carbon atoms, phenyl or cyclohexyl, and R.sub.3 and R.sub.4 =alkyl of 1-3 carbon atoms.