Emulsion is light sensitive and must be is dark and cool place when storing.
When using emulsion to coat your screen frame, work under either red light or yellow, i find that yellow lighting is more visual and easier on the eyes. coat both sides of screen evenly (screen coater is recommended) then let dry before exposing your image. you may put a little fan heater in front of screen to speed up the process but dont have it closer then 500mm other wise this could burn the emulsion & screen, i also recommend to turn screen around to dry both sides evenly. This process should take 30minutes
Firstly you need to have yor design on your computer either by draft or scanning. This can then be printed on to transparent film, the same stuff used for over head project (clear film) this can be bought from most office supplies.but be careful that you buy the right one for your printer as they are 2 type. inkjet or laser printers.
Once you have your film printed you can overlay it onto you emulsion coated screen tape it down on corners when in position. if you dont have a vacuum frame exsposure unit and most people dont when starting out, you can use a piece of glass from a picture frame to keep the film flat. The most cost effective exposure light is a 500watt halogen lamp which can be bought from most hardware stores, place the lamp above the screen no closer then 400mm, turn lamp on to expose your screen. As a guide, exposure time with the 500 watt lamp is around 20minutes. if using 1000watt 10minutes, 2000watt 5 minutes.
When exposure is complete removed glass & fillm and rinse out with water, your design will appear. Please also remember when preparing your design & film that whatever is black will wash away, The washed away part becomes your print. what is clear will be burn(expose to screen)