However I can give you some general advice.
1- Read carefully the instructions relateing to the ink and if they recommand using a CATALYST this is important, USE IT.
2- If your ink is the type which dries at room temperature, you must wait a minimum of 72 hours to fix the ink. After 8 hours the ink MAY APPEAR TO BE DRY, but it isn't: you must be patient and wait for the ink to fix permanently.
3- If your ink is the type which requires a dryer, you must dry it at 150°C for 2 minutes.
4- When you wash your t-shirt, remember that all ink manufacturers test their inks at a temperature of 60°C maximum.
There are no inks which allow washing above this temperature
5- If you already follow these instructions, it is possibile that your ink is defective. I suggest that you make a note of the batch number and contact your supplier.
I hope this reply is useful.

This is Franco Ratto,