A decorated bottle can look transparent on a sample table and still make the actual liquid level hard to read. Decide first who needs to see the level and under what conditions, such as a line operator at a fixed viewing station or a user holding the finished pack.
Check the finished bottle with representative fill
Fill samples at known low, target, and high levels using the actual formula where available. If a substitute is needed, document how it differs in color, opacity, and behavior at the liquid surface. Use the intended decoration and assembled components. Let the product settle as appropriate and record the bottle orientation, background, light, and viewing distance.
Ask observers to identify the level without seeing the reference marks or the fill setting first. Compare their readings to the known levels and record where glare, a dark print area, a gradient, or the wall shape blocks the view. Repeat at the relevant angles and lighting. If the purpose is a filling quantity check, confirm the quantity independently using the approved method. Adjusting an inspection window can make the boundary easier to see without changing the intended fill quantity.
The SamBound packaging catalog is available at sambound.com.
sambound.com
SamBound New Material Technology Company Ltd.
About Author
