A method for producing at least one well of plastic with an undercut on its outer side with the aid of an injection mould, which comprises a sprue runner, injection-side components and at least one slider with slider elements and a stripper as closure-side components, wherein the method comprises the following steps: closing the injection mould by moving together the closure-side components and the injection-side components relative to one another such that a cavity representing a counterpart for the well is formed in the injection mould between the slider elements; pressing liquid plastic through a section of the sprue runner in the slider and from the slider into the cavity with the aid of an injection moulding machine, wherein an injection point is respectively arranged on the side of the well or the cavity underneath the base; allowing the plastic to harden in the cavity in order to form the well together with a sprue; opening the injection mould by moving apart the closure-side components together with the well and the injection-side components relative to one another, wherein the sprue is torn off the well, wherein the slider elements are moved apart in order to release the undercut on the well; and wherein the slider elements are during opening of the injection mould only moved apart after the sprue has been torn off the well and pulled out of the section of the sprue channel in the slider, characterized in that a plurality of wells are produced in the form of a well strip, wherein the individual wells are connected to one another by means of connecting pieces; in that the undercuts or the connecting pieces respectively have - e.g. starting from the edge of the opening of the wells - a height d in the longitudinal direction of the wells, wherein the following applies to said height: 3.5 mm < d < 10 mm, preferably 7.0 mm < d < 10 mm; and in that the well strip is stripped off an additional closure-side component in the form of a closure-side core with the aid of the stripper. closing the injection mould by moving together the closure-side components and the injection-side components relative to one another such that a cavity representing a counterpart for the well is formed in the injection mould between the slider elements; pressing liquid plastic through a section of the sprue runner in the slider and from the slider into the cavity with the aid of an injection moulding machine, wherein an injection point is respectively arranged on the side of the well or the cavity underneath the base; allowing the plastic to harden in the cavity in order to form the well together with a sprue; opening the injection mould by moving apart the closure-side components together with the well and the injection-side components relative to one another, wherein the sprue is torn off the well, wherein the slider elements are moved apart in order to release the undercut on the well; and wherein the slider elements are during opening of the injection mould only moved apart after the sprue has been torn off the well and pulled out of the section of the sprue channel in the slider, characterized in that a plurality of wells are produced in the form of a well strip, wherein the individual wells are connected to one another by means of connecting pieces; in that the undercuts or the connecting pieces respectively have - e.g. starting from the edge of the opening of the wells - a height d in the longitudinal direction of the wells, wherein the following applies to said height: 3.5 mm < d < 10 mm, preferably 7.0 mm < d < 10 mm; and in that the well strip is stripped off an additional closure-side component in the form of a closure-side core with the aid of the stripper. 3.5 mm < d < 10 mm, preferably 7.0 mm < d < 10 mm; and in that the well strip is stripped off an additional closure-side component in the form of a closure-side core with the aid of the stripper.