Want to add a custom field in craft commerce plugin Is it possible to add a custom field in craft commerce plugin and is it a good idea to add it?
Yes, you can create new field and you can add it in it.
To add it, please go to admin panel and then follow the below mentioned sections.
settings &gt; product type &gt; add/select product &gt; product fields 
Then you can add custom field on field layout.
I hope this will help.