creating an underbase for screen printing

Hi there, new to the forum, hoping someone maybe able to help... I want to create an under-base for one of my graphics in preparation for screen printing.I have had a reply in another forum explaining how to do it in AI -

quote:  haven't used corel in many years but i would approach it the same way i do using illustrator. i add a stroke around the object to create the choke. i do a 0.5pt stroke which gives me a choke of 0.25pt (by default the stroke spreads from the edge of the object, 0.25pt inside object and 0.25pt outside).
i make the stroke colour 'global white' (not a spot colour) so it knocks out. or i turn the stroke into an object and subtract it from the main object.

 

Can anyone translate this process in Corel for me? For the record the underbase needs to replicate the image but very slightly inside the original lines if that makes sense.

 

Many thanks, Jade