Boletopsis grisea likes a high pH but not immediately. I let it warm for about 20 minutes and then shifted it to pH 9. I kept the temperature up high around 165 degrees for an hour. I put the iron swatches in last, after I removed the alum and tin swatches because the reaction between the Boletopsis and iron is such that it will contaminate the alum and tin swatches. In general this is a really good practice to abide by for all natural dyes but for the studies in the Mushroom Color Atlas I only did it where noted.