Method for manufacturing at least one straight flexible strip for horology made of micromachinable material, comprising an upper surface and lower surface which are parallel, including at least the steps consisting of: - taking at least one substrate wafer made of micromachinable material, including an upper face and lower face which are parallel; - forming a plate of the required thickness with a single said substrate wafer (511; 811), or by joining a plurality of said substrate wafers (711; 712); - affixing a first, upper mask (512; 714; 812) including at least one upper window (513; 715; 813) on the upper face of said plate, and a second, lower mask (514; 716; 814) including at least one lower window (515; 717; 815) on the lower face of said plate; - etching said plate, to a lower etch depth than said required thickness, from an upper side at each said upper window (513; 715; 813), creating, adjacent to said upper surface, a first peripheral edge surface tapered with respect to said upper surface, over a first height, - and creating, from a lower side at each said lower window (515; 717; 815), remote from said upper surface and adjacent to said lower surface, a second peripheral edge surface reverse-tapered with respect to said first peripheral edge surface; - removing said first, upper mask (512; 714; 812) and said second, lower mask (514; 716; 814), characterized in that said first peripheral edge surface and said second peripheral edge surface are symmetrical with respect to a median plane equidistant from said upper surface and from said lower surface, and in that said first, upper mask (512; 714; 812) and said second, lower mask (514; 716; 814) are of identical geometry and disposed in symmetry with respect to a median plane located at mid-thickness of said plate, and in that the sum of said etch depths is greater than or equal to the thickness of said plate, so as to delimit at least one straight flexible strip whose height is equal to the thickness of said plate, whose width is defined by the profile of said first, upper mask (512; 714; 812) and said second, lower mask (514; 716; 814), and whose edges are as-etched. - taking at least one substrate wafer made of micromachinable material, including an upper face and lower face which are parallel; - forming a plate of the required thickness with a single said substrate wafer (511; 811), or by joining a plurality of said substrate wafers (711; 712); - affixing a first, upper mask (512; 714; 812) including at least one upper window (513; 715; 813) on the upper face of said plate, and a second, lower mask (514; 716; 814) including at least one lower window (515; 717; 815) on the lower face of said plate; - etching said plate, to a lower etch depth than said required thickness, from an upper side at each said upper window (513; 715; 813), creating, adjacent to said upper surface, a first peripheral edge surface tapered with respect to said upper surface, over a first height, - and creating, from a lower side at each said lower window (515; 717; 815), remote from said upper surface and adjacent to said lower surface, a second peripheral edge surface reverse-tapered with respect to said first peripheral edge surface; - removing said first, upper mask (512; 714; 812) and said second, lower mask (514; 716; 814),