Electrostatographic developer composition

A method of non-contact heat fixing electrostatically deposited dry toner particles after their deposition or transfer onto a substrate, the improvement comprising utilizing an electrostatographic developer composition comprising carrier particles and toner particles with a toner particle size distribution having a volume average particle size (T) such that 4 .mu.m.ltoreq.T.ltoreq.12 .mu.m and an average charge (absolute value) pro diameter in femtocoulomb/10 .mu.m (C.sub.T) after triboelectric contact with said carrier particles such that 1 fC/10 .mu.m.ltoreq.C.sub.T .ltoreq.10 fC/10 .mu.m, wherein

• (i) said carrier particles have a saturation magnetization value, M.sub.sat, expressed in Tesla (T) such that M.sub.sat .gtoreq.0.30 T
• (ii) said carrier particles have a volume average particle size (C.sub.avg) such that 30 .mu.m.ltoreq.C.sub.avg .ltoreq.60 .mu.m
• (iii) said volume based particle size distribution of said carrier particles has at least 90% of the particles having a particle diameter C such that 0.5 C.sub.avg .ltoreq.C.ltoreq.2C.sub.avg
• (iv) said volume based particles size distribution of said carrier particles comprises less than b % particles smaller than 25 .mu.m wherein b=0.35.times.(M.sub.sat).sup.2 .times.P with
• M.sub.sat :
• saturation magnetization value, Meat, expressed in T
• P:
• the maximal field strength of the magnetic developing pole expressed in kA/m
• (v) said carrier particles comprise a core particle coated with a resin coating in an amount (RC) such that 0.2% w/w.ltoreq.RC.ltoreq.2% w/w.