Lines define shape and shapes withing shapes. Without lines we couldn't distinguish one shape from another, though we are often unaware of the lines themselves. Lines are a component of our visual acuity ... they are part of a composite along with color, density, depth, plane and perspective. The challenge in this prompt, to me, was picking pictures that demonstrate the subtlety of line as well as the more obvious lines. To say this was fun is understating ... as is the case in all of Bonnie's prompts.
This old building is the perfect example of the use of line in Architecture. I tweaked this picture in PSE using levels, brightness/contrast and then turning it into a black and white Photograph. I then used the pencil filter to make it like a pencil drawing. Finally I added pdpa Panache, Soft & Subtle texture.
Here the lines are secondary to the overall picture. What you see is trees, but the lines define them. I used my same tweak routine in PSE, the Dry Brush and Posterize filters, added pdpa Greenglaze overlay. Using a mask/brushed out the trunks of each tree so they stood out.
In this picture, the wire lines suggest a shape that you are all familiar with even thought it is clearly not a real chicken. I used Poster Edges Filter then added pdpa Spring Choir Texture. With the mask I brushed out the chicken and the flowers.
Here you see leaves, you see grass, you see lines that define a color change. There are also lines in the leaves, but do you really see the lines or do you just see the leaves?
I used my usual tweak then added pdpa Panach Morning Glory texture. Using the mask/brush technique, I created new lines while muting lines within the new lines. I then used the same Morning Glory texture as a frame.
This is my first ever attempt at Zentangle. Zentangle is an art form that is all about lines. I have to admit, I cheated a little. I used a PSE brush to get the water lines and I am not sure you are supposed to start out with a figure in mind. But, it does demonstrate how important lines are to a composition.
Oh my, what fun ... thanks again, Bonnie ...