Following is the result of investigation:
This issue happens with blends created when stroke with flat edge is applied to one path then later variable width profile is changed.
Workaround: Select the blend object, Release the blend, change path’s Variable width profile to Uniform, and then apply desired Variable width profile again, Now try apply Blend.
An error occurred while saving the commentRyan commented
I've recreated this on 2 machines. Mac OS 10.13.4.
lino cut turial file here with a test
some blend variations
https://www.dropbox.com/s/31vkqgd0z7yxxq5/moire_blend_interp.ai?dl=0Ryan shared this idea ·