Taut smoothings of arcs and curves

We study the geometric and combinatorial effect of smoothing an intersection point on a collection of curves or arcs on a surface, make progress towards answering the question of whether every taut curve has a taut smoothing, and answer the analogous question in full for taut arcs with fixed endpoints and for taut multi-curves and multi-arcs with at least two non-disjoint components. We deduce that for every Riemannian metric on a surface, the shortest properly immersed arcs with at least k self-intersections have exactly k self-intersections, and prove a partial monotonicity result for the marked length spectrum of curves on orientable surfaces.