A method of manufacturing a brush or a paintbrush, in particular a varnish brush, by anchor-free fastening of at least one bristle bundle to a holding portion of the brush or paintbrush, wherein the at least one bristle bundle is fastened to the holding portion in an anchor-free manner, and the at least one bristle bundle to be fastened in the brush or paintbrush is manufactured by means of the following steps: (a) providing a bundle carrier which has a front side and an opposite rear side and at least one continuous opening connecting the front and rear sides, (b) uncoiling of bristle material from at least one bobbin (24 - 28) in the form of a strand (30 - 34) made up of a plurality of fibers arranged side by side, (c) inserting the bristle material that has not been cut to length into the bundle carrier, in particular from the rear side and in particular substantially perpendicular to the rear side, and (d) subsequently cutting off the bristle material projecting into the bundle carrier, so that a bristle bundle formed in the bundle carrier is formed, characterized in that the bundle carrier is the holding portion of the brush or paintbrush itself, wherein the holding portion is a portion that continues in one piece into the rest of the brush or paintbrush body or is a separate, previously manufactured component which is part of the later brush or paintbrush body. the at least one bristle bundle is fastened to the holding portion in an anchor-free manner, and the at least one bristle bundle to be fastened in the brush or paintbrush is manufactured by means of the following steps: (a) providing a bundle carrier which has a front side and an opposite rear side and at least one continuous opening connecting the front and rear sides, (b) uncoiling of bristle material from at least one bobbin (24 - 28) in the form of a strand (30 - 34) made up of a plurality of fibers arranged side by side, (c) inserting the bristle material that has not been cut to length into the bundle carrier, in particular from the rear side and in particular substantially perpendicular to the rear side, and (d) subsequently cutting off the bristle material projecting into the bundle carrier, so that a bristle bundle formed in the bundle carrier is formed, characterized in that (a) providing a bundle carrier which has a front side and an opposite rear side and at least one continuous opening connecting the front and rear sides, (b) uncoiling of bristle material from at least one bobbin (24 - 28) in the form of a strand (30 - 34) made up of a plurality of fibers arranged side by side, (c) inserting the bristle material that has not been cut to length into the bundle carrier, in particular from the rear side and in particular substantially perpendicular to the rear side, and (d) subsequently cutting off the bristle material projecting into the bundle carrier, so that a bristle bundle formed in the bundle carrier is formed, characterized in that the bundle carrier is the holding portion of the brush or paintbrush itself, wherein the holding portion is a portion that continues in one piece into the rest of the brush or paintbrush body or is a separate, previously manufactured component which is part of the later brush or paintbrush body.