Humidity & Room Temperature
Different adhesives have different recommendations for optimal humidity but usually it's around 45-55%. If your humidity is too low you will find that you will be disturbing already placed lashes when you isolate, knocking them off or they will set at undesirable angles. Too high and your adhesive will have to started to set before it even touches the natural lash. It will develop a skin on it and look gooey and you can expect your clients to mention some retention issues when they return.
Make sure you get yourself a hygrometer, they are fairly cheap to buy and can become a necessity when ensuring you have the perfect environment for lashing.
You will also find that the temperature of the room will affect your adhesive too. I like to keep my salon at about 20 degrees celsius, this seems to be the optimum temperature for me to lash efficiently. As a side note, beware of sitting too close to a heater in colder months. I have recently moved salon and my room gets very cold so I have to heat it up quickly. I noticed that at some points in the day my adhesive just stopped grabbing. The humidity was perfect and the hygrometer said the temperature was perfect too so I was stumped.
However, I did notice that I would feel very hot around the time my adhesive would give up and I realised it was because I was sitting by the heater. The temperature would drop, the heater would come on full blast to warm the room up and was affecting my adhesive. The hygrometer wasn't able to pick up the temperature change in just that small area so was reading the temperature as being fine.
If you ever experience problems with your adhesive , check your humidity and room temperature because that is most likely the cause!
I am lucky in that all the years I have been lashing I have had very few clients that have reported back with retention issues and I would be stumped as to why their lashes didn't last. But now I know about humidity it all makes sense. I remember one client told me that all her lashes I had done for her infill had all fallen off the same day and I couldn't figure out why. I remember that there was a particularly bad thunderstorm the day she had them and the humidity must have been through the roof. This would have set the adhesive almost instantly so the lashes just wouldn't have bonded.
Humidity can make such a difference to how well your lash extensions bond but for years I had absolutely no idea how it affected my work and why I should be monitoring it. If all of a sudden your adhesive seems not to be grabbing so well, if when you brush through you get lashes just pinging off, then the probable cause is the humidity. Depending on where you live and and the time of day you could even find that you set off to a brilliant start but out of the blue your lashes just refuse to bond. It's incredibly frustrating!
I have been battling with it lately, especially as I like to use a very fast setting adhesive for volume that requires a very specific humidity level. It can be difficult to get your working environment up to the right level. I have a humidifIer and a dehumidifier (but if I need the humidity to rise quickly I grab the kettle!!) and of course the trusty hygrometer.