Welcome!
There is a fair amount of variability in fabrics. You are really best off doing some tests with the fabric you are using. This is a popular method (though you might want to enlarge a little for fabric):
Maybe start somewhere around 500 / 60.
Searching in the Beyond the Manual section (the only section where custom settings are allowed) for “cotton fabric settings” will also turn up other people’s settings.
Thank you very much. This looks like a fantastic tool. I will keep it in my toolbox.
The Material Test proved to be wonderful. We cut 30 sets of a four-part design using Batik fabric on Heat and Bond UltraHold using a speed of 500 and power of 45. This cut thorugh the fabrid and the Heat and Bond and mostly through the paper backer, leaving the parts very lightly attached and not blowing in the wind. The bigger parts separated from the scrap very easily. The smaller perts we left together and will remove them as needed. We are very, very happy with our purchase. It is miles ahead of our current cutter, a Silver Bullet, and much easier to use. We weren’t sure if we would part with the Silver Bullet prior to trying our Glowforge, but there is no question now that we no longer need it. Thank you for your help evermorian.
Wonderful! I’m glad it worked out so well.
Thank you for sharing your experience. I hope you will share some of your projects here at some point.
I used your settings (500 speed, power 45, height 0.03) on satin with Heat&Bond ultrahold, and it worked perfectly. The paper doesn’t cut through, but the applique peels off the paper and irons on just fine.
Welcome @leahwrenn to the community.
You will discover that the interaction and cross seeding of ideas among members are one of the best parts of owning a 
.
Hope to see what you create!