Every lash brand recommends a slightly different range as the lash glue bottles are all formulated differently. However, a "good" humidity range is typically between 45% and 65%, while the temperature should be around 20-25°C. The best approach is to directly consult the manufacturer for specific recommendations. For instance, at Lash Jungle PRO, we recommend the following conditions for all our adhesives: Humidity: 50-65% Temperature: 21-25°C If the room's humidity is higher than the ideal level (above 65%), the cyanoacrylate (the main ingredient of your glue) will be overly activated by the excess moisture in the air, which speeds up the curing process. This means the glue may dry even before you apply the extension to your client's natural lash. On the other hand, if your workstation is cold and dry - especially during winter - your glue will dry more slowly than normal. Pro tip: Use a hygrometer to monitor the conditions in your lash room. Based on its reading, use a dehumidifier, humidifier, air conditioner, heater, or fan to control the temperature and humidity as needed.