7 foot chamber, but how long are you leaving it in there? should be in the heat no less than 2.5 minutes, and temp on ink should be around 320 minimum. JBlue is right, go with a higher mesh count, 156-180 and you won't leave a huge globby deposit. Maybe add some penatrant to dig deep in the fabric. Don't try to achieve a bright opaque white look on press, that's way too much, you will have your opacity at the end of the fabric's discharge. Give that a whirl. Just remember, the more ink you cake on there, the longer it has to be in the oven.