It is vital to have the dimensions of your stopper cap and bottleneck diameter. Ideally, you want the shrink cap to be 1-2mm larger than the widest point of your stopper and bottle. If the shrink cap is too small, the heat may rupture the cap. If the shrink cap is too large, it may not seal properly.

The ideal temperature setting for a handheld heating device is 180-260 degrees Fahrenheit. We recommend holding the top of the shrink cap down until the base is secure to prevent an air bubble at the top of the cap.

For steam heat tunnels. we recommend setting the temperature beween 260-280 degrees Fahrenheit. It is important to ensure consistant airflow around the neck. For best results make sure the bottlenexk is dry prior to heating.

Our shrink caps work with most heat tunnels; however, we recommend testing with samples. We do not recommend using heat tunnels where the bottle is either placed on its side or inverted.

Our closed cap shrink caps have a spacing bead that makes them compatible with most automated bottling lines. We recommend testing 100-200 shrink caps before starting the line to make any adjustments as necessary.

Our open cap shrink caps do not have a spacing bead but are still compatible with some lines. Testing is required to determine if they will work with your bottling line or if the caps would need to be placed by hand.