Put in the most basic terms, screen printing (sometimes known as "silk screen printing") uses a series of stencils to decorate a substrate.
A screen printed transfer (also known as a plastisol transfer) is an image which has been screen printed onto release paper. Instead of being directly screen printed onto a shirt or other item, the design is printed onto transfer paper, then applied with a heat press. Screen printed transfers can be single or multi-color, and heat apply in seconds to any number of items, such as T-shirts, sweatshirts, shorts, jackets, and caps.
Though screen printed transfers use the same inks and processes as other types of screen printing, the use of transfers holds several advantages.
Print on Demand – Transfers are great for events where you are unsure of how many shirts will be sold. The garment doesn't have to be printed until it is sold, so there will be no leftover printed merchandise.
Fill-Ins and Last Minute Orders are Easy - Screen printed transfers allow an inexpensive way to be prepared for last-minute fill-in orders. Replacement shirts and last-minute additions won't be a problem.
Quality – Screen printed transfers are just as durable as direct-printed garments and often provide better-looking results.
Save Time and Money – Gang sheets (which feature more than one image on the same sheet) help make transfers even more economical, especially for sports league sponsors, caps, and heart-size prints.
Offer Better Customer Service – Unlike traditional screen printing, where all shirts need to be printed at the same time, transfers can be printed as products arrive. If a shirt is on back-order, you can print the rest of the order, then finish in seconds when the back-ordered shirt arrives.