Abstract: A monomer having a pair of hydroxy groups held in a fixed relationship (e.g. a dihydroxybenzene) is diesterified with a compound having a polymerisable group, e.g. to form a diacrylate. After polymerisation with a crosslinker, the polymer is hydrolysed. The dihydroxy-monomer is removed, leaving a polymer with pair of carboxyl groups held in spatial relationships determined by the dihydroxy monomer. Thus a range of subtly different polymers can be prepared by using different dihydroxy-monomer templates. The polymers are desirably swellable. They can be used as selective binding materials, e.g. in chromatography or analysis.