The invention provides a benefit agent delivery particle having an average diameter of less than 50 micron comprising at least one shell formed by a step-growth polymerisation reaction, preferably involving an isocyanate monomer, more preferably a urethane and/or a urea, interior said shell, at least one region formed by chain-growth polymerisation reaction (preferably a free-radical polymerisation) which does not involve an isocyanate, c) optionally, a benefit agent interior to said shell, and/or a deposition aid exterior to said shell. The invention further provides a process for the preparation of such particles wherein the shell is formed prior to the chain-growth polymerisation of the at least one region interior of the shell, preferably be forming the shell at a temperature at which the chain-growth reaction is inhibited. The invention further provides fully formulated products, preferably liquids and gels, which contain said benefit agent delivery particles and a method of treating substrates using said products.
