When considering static frames, the specs of the particular mesh used on the frame is what's important. The amount of newtons the screen is stretched to should be in direct relation to the mesh's thread diameter & % open area & ink volume. To achieve optimum performance of the particular static screen you are paying for, it should be stretched to the manufactures spec. The mesh's elongation properties must also be considered so that after work hardening, the tension fall's within the optimum %open area, whether it is 15, 20, or 25 newtons. This can only work if you know the characteristics of the mesh and trust that the supplier does too. Another way to control this however is bringing the stretching in-house. And I figure it is simpler to stop and start over on retentionable frames than it is on static glue frames.