Well I live and learn, thanks for the reply. The irony is that my enlarger has a vertical column, which means that these large RRB easel blades and borders would force a reduction to the "useful size" to a landscape height of 10 inches or 25cm, even if I had intended on using a larger RRB easel, so the "12x16" is the maximum I can use on my enlarger. Luckily I have this Kaiser easel still, as I had been thinking of consolidating my darkroom kit a bit and getting rid of this. Now the question is whether any of my recent Bronica photos deserve to be printed at 12x16!