Next up: the upper arm. Using the paths I had created earlier, I made selections for the upper and lower plate and copied each into a seperate layer, rotated them clockwise and counter-clockwise respectively. Then I highlighted some of the edges for depth and moved them apart (image 15). Now to show the inside of the arm. Like I did with the head, I made a selection where the arm would reveal the hardware and then alt-connected it to the hardware image in the layer above it (image 16). After resizing, rotating and positioning the image of the hardware to the form of the arm, I added some shadows with the burn tool for depth, with the armplates as guides (image 17).Making shadows is quite a delicate task. When not done right, shadows can be a dead-giveaway that an image was altered. For me, using the burn-tool with different brush sizes, exposures and ranges (highlights, midtones and shadows) gets the best results. And sometimes, when the image allowes it, using the images own shadows can work as well. Or even better.Back to the arm. Revealing the thickness of the "cyborg-flesh" (of the arm and the arm plates, in different layers) is done in the same way as with the head (image 18). Then I worked on the duplicate image of Catherine to highlight and darken the edges of the outer arm here and there, as well as some shadows (image 19).