Some of you have mentioned your difficulty in creating strings. Whenever I am confronted with that, I resort to something real simple . . . stripes! . . . lines, ribbons, pipes, moldings, borders.
In one of my past lives, I was part owner of a frame shop. I did not do the actual "cut the frame" part, but I often did the custom mat jobs . . . with either "French lines," marbled paper borders or calligraphy.
Now, this has morphed into creating patterned borders around art or photos in a Zentangle way whether with pen and ink or with brush and color.
There is a basic simplicity of tangling within the string of a stripe and then shading on the outer edges to tie it all together.
This is also a fun exercise/challenge to do with tangles that you wouldn't immediately think of as "border" tangles.
I am especially attracted to the unevenness of these stripes and borders because it's obviously hand-made . . . not machine made. So, no worries if your strings aren't perfectly straight or parallel!
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