I've given up using diluted white vinegar as a stop in RA4, mostly because I was getting blue streaks on my white borders from time to time. This is to ask why I might have been getting those streaks. I noticed our white vinegar at home is 6% acidity, I've been diluting it 1:4. Is this too strong? Might the stop be carried into the blix and interfering in its function? If so, is the role of stop not only to halt development but also to prepare the paper for blix?