Dear people smarter than I am, I hoped to use some time around the [rented, very short-term] house after the birth of our baby for making some small photos of her on-site. I can develop my film, but have nowhere to print. Lacking darkroom and not able to set anything up temporarily. Centennial POP would have been perfect for my use, but found it was long discontinued. So I turned to Argyrotype for easy processing without a darkroom; it gave me good results many years ago. Been working with some Bostick and Sullivan pre-mixed argyrotype sensitizer on Arches Platine, with 6x6 negatives. Figured Platine was a can't-miss, being designed for this. Coating with a puddle pusher on 3"x3" squares of paper, printing in a brand-new Photo Formulary frame. Having problems getting any sort of decent image. The issue looks, to me, to be image runoff. The areas outside the negative are printing out to the "plated" or "solarized" appearance just fine. But in the initial rinse, much of their density is washing right off. Same with the film base edges and shadow areas in the image. And, despite attempts at both single- and double-coating the paper, the image is a bit mottled, as if some of the sensitizer has peeled away...correspondingly, the negatives have bits of dark goo on them which I can only assume is sensitizer. Tried wiping them off with alcohol to modest success, but they seem pretty ruined. It is REALLY hot and humid out, if that's a factor. Any ideas to what's causing my problems? I'm focusing on the issue of lost density and mottling before looking at any fine-tuning of my negatives' exposure/development...if I was simply getting less-than-optimal results within the image area alone, I wouldn't be so confused. But even the unexposed film base areas are washing away. Seems to be something more mechanical/procedural causing my problems. Am I coating too lightly/thickly, or is it not dry enough? Just too humid outside right now for this? Am I missing something special that needs to be done for the Platine paper to take on the sensitizer properly? Can I add Tween or some other additive to help? Could Platine simply be an inappropriate paper? (Figured it was a can't-miss, being specifically made for these purposes...) Thanks for any advice you can offer.