Product Subscription Question / Advice / Suggestions

[sweetstash]

Hello everyone,

I sell cross stitch supplies.  I have a designer that releases a new design approximately monthly... but there is no set schedule.  I have many customers who purchase every one when released, but like I said... monthly is not a guarantee.  Is there a way to set up a subscription where when I add a new product to a certain collection (or some place I have to add or tag) for them to be on an auto order subscription when it's released?  Or can subscriptions only be done on an exact time frame... not per release?

Hope this makes sense.