I'm new to I.S. I import jpegs into I.S. to trace them. Today after importing a jpeg, I clicked on 'Add Layer', named it TOP. Clicked on 'Layers..." to see all layers and there was no base on Layer 1. The image is there and obviously on the base (Layer 1) layer but there is no 'Lock', opacity is inoperable. Is there an 'on/off button that might prohibit the base layer from showing because the box for it is just not there.