Photoshop can adjust the dots to eliminate things that plague screeners, such as dot gain, screen angles and line counts. Inkjet, laser and thermal printers are the common types found in a screenprinting shop. The inkjet printer is dual purposed. You can also use your inkjet printer to print proofs. The laser printer has really become the workhorse of office printing.
Lasers are quite reliable and can print other office documents as well as separations.
You will need at least a 600 dpi printer that is capable of laying down good toner coverage. One printer with a good reputation for printing separations is the Xante Screenwriter 3. There are also color laser printers, commonly called CLCs or color laser copiers. Thermal printers do not use toner. Instead, they use heat to change the color of a thermally active film into a color which blocks UV light.