I'm trying to print a very thin negative on a large paper (30x40 cm). I thought using split grade printing would ease the process but my initial attemps were not very successful - I found no highlights but shadows everywhere. I'm printing with geometrical time scales and went down to quarter exposure steps but still...No midtones. How should I go on? What is a good way of tackling a thin negative? I have access to dektol and also some selenium toner, but not very much more than that.