Hey there!
This should be the right forum for your question :)
I haven't been able to find a t-shirt app that mentions the ability to do 'flock' printing on shirts - so I can't confirm.
If I were you, I would send a message to each of our shirt fulfillment apps, using the contact info in the 'Support & Sales' section in the app pages.
Here are some of the apps that offer shirt fulfillment:
- Printify (https://apps.shopify.com/printify)
- Print Aura (https://apps.shopify.com/print-aura)
- Printful (https://apps.shopify.com/printful)
- Merchify (https://apps.shopify.com/merchify)
- Teelaunch (https://apps.shopify.com/teelaunch-1)
- Scalable Press (https://apps.shopify.com/scalablepress-t-shirt-fulfillment)
- Level Press (https://apps.shopify.com/levelpress-dev)
- Spreadshirt (https://apps.shopify.com/sprd-dev-app)
- PersonalizationPop (https://apps.shopify.com/personalizationpop)
- Pressera (https://apps.shopify.com/pressera)
- Teespring Fulfillment (https://apps.shopify.com/teespring-fulfillment)
- Teescape Fulfillment (https://apps.shopify.com/teescape-fulfillment)