Abstract: Disclosed is a plastics composition comprising a thermoplastic blend comprising: (1) 5-95 wt % of a polyamide (PA) and 95-5 wt % of a polyester (PE) incorporating 1-50 wt % of an aliphatic dimer fatty acid, (2) 0.01-30 parts by weight of a compound having at least one ethylenically unsaturated group or propylene group and further having a carboxylic, acid anhydride, acid amide, imido, carboxylic ester, amino or hydroxyl group per 100 parts by weight based on the combined weight of PA and PE, (3) 0-90 parts by weight of a polyester not modified with dimer fatty acid per 100 parts by weight based on the combined weight of PA and PE. Preferably the polyester (PE) is a polyethylene terephthalate or polybutylene terephthalate modified with di-oleic acid. The blends have a greatly improved elongation at break and are readily spinnable.