Tack concerns how a prepreg adheres during handling; drape concerns how it accommodates a shape. A material can be described on both bases. Neither term alone establishes the cured component’s properties or suitability for a particular mould geometry.
Report the observation precisely
A ply that will not remain positioned and a ply that will not conform without folds present different observations. Identify the material, relevant handling condition and affected geometry. Avoid grouping every layup difficulty under a vague claim that the prepreg is “too stiff” or “bad.”
Keep material status with the review
Gurit’s processing guidance discusses handling behaviour within the prepreg process. Use the exact supplier documentation and recorded material history when the manufacturer reviews an issue. Do not improvise a change in handling or processing conditions from a general article or a comparison with another resin system.
Connect forming trials to the actual part
If a trial is used to review a difficult region, identify the material and geometry it represents. Record what the trial establishes and what still requires evaluation. A convenient layup demonstration is not automatically evidence for the full production construction. The enquiry should define the finished component and necessary evidence while leaving process decisions to the agreed technical review.
Further reading: Gurit: prepreg processing guide.