There are several types of emulsions out there on the market, so how do you decide on which one to get? You will want to ask yourself a few questions:
1) What level am I at? Am I a beginner, intermediate or pro?
2) What type of exposure unit do I have?
3) What type of ink will I be using?
4) What type of area do I have to wash out emulsion?
All of these are important questions to ask to save in future headaches and to ensure you're not wasting time or money on emulsion. When it comes to emulsion, there are 2 categories: Presensitized or Diazo Mixed. Presensitized emulsions are sensitive emulsions that expose quicker, last longer (longer shelf life) and expose fine detail beautifully. The downside of this emulsion is that it is VERY sensitive. You have a very narrow window of error, as little as 10s, on exposure, to get it right. You do not want to use this emulsion if you're just starting out, have a hobbyist's or beginner's exposure unit (without a timer), or do not have accommodations to wash out your screens in a darkroom. In fact, this emulsion is so sensitive, if you were to take it outside to start washing out, even the light from a cloudy day (or in the shade) would start exposing the image fast enough, that you would not be able to break through the emulsion. These emulsions are great to work into, but you may run into more issues than properly exposed screens, if you get into this emulsion too soon.
The Presensitized emulsion PROS and CONS:
1) Exposes faster
2) Longer Shelf life (up to 1 yr)
3) Great detail
1) very sensitive- not for units without timers and needs to be washed out in UV free area.
2) if slightly over or under exposed, you will have wash out issues. Takes as little as 10s!
3) More expensive.
Diazo mixed emulsions require mixing to activate the emulsion. Once mixed, these emulsions will last about 2-3 months if stored properly (best place is in the fridge without freezing). These emulsions take longer to expose, however, are more forgiving. If you go over or under by 30s-1 minute, you rarely have to worry about it. These emulsions work great with units that do not have timers and can be washed out under UV light successfully (most of the time) without any issue. The emulsion is cheaper and going to be less of a headache for those getting into screen printing. The emulsion still has the capability to retain higher detail and offers great prints from the low to high range of the detail spectrum.
Diazo Mixed Emulsions PROS and CONS:
2) Forgiving on under or over exposure.
3) Can be washed out under UV light.
4) Still offers good detail.
5) USER FRIENDLY.
1) Shorter life span.
2) Have to mix to use.
The emulsions we sell that are Presensitized are the Hifi, SVP and Ulano QTX. The emulsions we sell that are Diazo Mixed are the WBP, DXP (RXP) and the DCM.
After figuring out which emulsion type would be best for you, the final question to answer is- what type of ink am I using?
Waterbased/Discharge (includes RyoCharge) ink- WBP, short runs with the Hifi.
Plastisol ink: Hifi, SVP, DCM, DXP, WBP
Solvent Based Inks: DCM, SVP