2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/77201A persistent lamination for a knot K is an essential lamination in the complement of the K, which remains essential after every non-trivial Dehn surgery along K. In particular, this implies that all of the Dehn surgery manifolds have universal cover R^3. This paper presents a method for building tangles T with the property that every knot K obtained by tangle sum with T has a persistent lamination. A natural generalization to 2n-string tangles is also given.13 pages, with 16 figuresGeometric Topologytext