Thermosetting resins which are essentially vinylbenzyl end-capped ethers of the oligomeric condensation products of certain dihydric phenols and formaldehyde are readily polymerized to give an extensively cross-linked polymer particularly useful in printed circuit boards and similar laminates. Effective cost reduction may be enjoyed by replacing up to 50 % of the vinylbenzyl moieties by other groups, such as alkyl and benzyl groups, without destroying the usefulness of the resulting thermosetting resins.