Screen printing: The one thing I've used Photoshop for in the past is to change an image to black/white and to simplify it, in order to use it for screen printing with a Thermofax screen. I've learned some additional ways to manipulate the image in this class. Here's a photo of some sharp leaves from a desert plant in Arizona, and then two different images derived from it. I think they would both be interesting for printing on fabric.
This particular lesson in the class was especially geared towards quilters who might want to simplify a photo in order to do an appliqué version of the image (usually with fused fabric). I don't do that type of quilt myself, but I decided to do a photo of that sort also, in order to practice more. In this photo of my mother-in-law Dorothy Amor--may her memory be a blessing--and my niece Alison Hardie, I think it's interesting how the warmth of their relationship is maintained in the b/w version. I was also happy to be able to take out the poster in the background.
Determining quilting patterns: Deciding on how to quilt a piece is rarely an easy decision for me. Once I narrow the choices, I usually do actual quilting samples, but getting to that point is a challenge, as it's difficult to get a sense of how the whole piece will look quilted. Sometimes I've used a large piece of clear plastic, laying it over the quilt and drawing on it with crayon (though usually just for a section of a quilt). Turns out I can do the same kind thing in Photoshop, but mush easier to make changes, I can test on an image of the whole quilt, and there's no plastic glare!
Here's a photo of a quilt top I'm working on at the moment (Cobblestones Quilt pattern by Kevin Kosbab, from The Quilter's Appliqué Workshop).
Here's the photo with quilting marked:
You can see better what I've done when I segregate out the layer on which I did the drawing. I tried out various kinds of squiggles in the "cobblestones." I don't like the circles in the second row, but the others all are decent possibilities.
Straightening edges: Even though my quilts have 90-degree corners, they don't usually look that way in photos, as in "Late March," below (see how the bottom edge looks pulled in). This is because of camera distortion that you get unless the camera is very carefully positioned, not something I can do for the snaps I take. Lo and behold, you can correct for this in Photoshop.
Playing with "fabric swatches" from the web: Photoshop allows you to pull fabric samples from photos on the web, and play around with patchwork designs. The black/white fabric below is Line Leaf in Black from the Bark and Branch collection by Fabric Bubb. I added a "solid fabric" by using the paint bucket tool in Photoshop. This was fun, but time consuming. Reminds me that it's OK to cut into fabric I have on hand, even just for the sake of playing around!
There were more things in the class also--brightening, intensifying, and sharpening images. I highly recommend the class! The lessons are really clear (printable handouts and video demonstrations), and the feedback from the instructors on assignments and questions is prompt and very helpful. Again, if you're interested, you can sign up to be contacted in advance about classes that will be offered.