Listings on Folksy last for 120 days (approx. 4 months). During that time, you can increase or decrease the number of items available by changing the quantity from the 'manage listings' screen, or by editing the individual listing. The maximum quantity for any listing is 100.
If you increase the quantity available, you will be charged 15p + VAT for each additional item (unless you have free listings on the Plus account). Changing the quantity of a listing does not change the expiry date of the listing.
There's a blog post explaining the re-stocking functionality and in particular the difference between listings and items.
Renewing Expired Listings
After 4 months, your listings on Folksy expire, regardless of whether they are in stock or sold out. That means that you do need to keep an eye on the listings that you re-list from the expired tab. You can arrange listings by stock level by clicking 'in stock' at the top of the 'Expired' tab in the manage listings table.
To renew an expired listing, go to the Expired tab, select the items you would like to renew and click 'renew' at the top of the table. You will be asked to confirm, and this will re-list the selected items for another 4 months and you will be charged again at the usual rate.
Renewing listings before they expire
You can renew items at any time during their 4 months listing if you wish. You will be asked to confirm, and this will reset the expiry date to 4 months from the renewal date (i.e. you will lose any time that was left on the previous listing time), and you will be charged again at the usual rate.