Transparent blend or alloy comprising, by weight, the total being 100%: (A) 1 to 99% of at least one copolymer constituent: which is amorphous or has a crystallinity ranging up to semicrystallinity; and which comprises: (A1) amide units, among which is at least one cycloaliphatic unit; (A2) flexible ether units; (B) 99 to 1% of at least one polymer constituent selected from: (Ba) semicrystalline copolyamides comprising amide units (Ba1) and comprising ether units (Ba2), (Bb) semicrystalline polyamides or copolyamides without ether units, (Bc) transparent polyamides or copolyamides without ether units, which are amorphous or weakly crystalline, and alloys based on such polyamides or copolyamides; and (C) 0 to 50% by weight of at least one polyamide, copolyamide, copolyamide comprising ether units or alloy based on such polyamides or copolyamides other than those used in (A) and (B) above. The resulting blend or alloy has a high transparency such that the transmission at 560 nm on a plate 2 mm thick is greater than 50%.