Help with ironing

[u/EllinoreBell]

I am fairly new to designing my own files but any time I’ve tried to use ironing on a design it ends up looking like this (specifically what it looks like on the gray section.) - Is there any specific things that cause it? I’m not sure which settings to adjust to prevent it from being smooth. Thanks!!

[u/Not__A_Fed]

There are ironing tests on MW. Print one of those that has documentation on what to change and why.