Read the directions supplied with your specific adhesive and test the complete material combination on a hidden area or spare sample.
Plastic is not one material
Rigid acrylic, flexible phone cases and coated household objects may look similar but behave differently. The product code, finish and flexibility matter. Check both the object guidance and the adhesive label before choosing a visible project.
Run a small compatibility test
Use an inconspicuous spot or, preferably, a spare sample of the same plastic. Look for softening, clouding, colour change, poor wetting or a weak bond after the full directed cure.
Account for flex
A rigid decoration attached across a bend can lift even when the adhesive bonds well to the plastic. Keep stones away from hinge lines, corners that stretch during installation and areas squeezed repeatedly by the hand.
Protect the object’s function
Do not cover ventilation, buttons, sensors, charging openings or safety markings. For valuable electronics and precision parts, follow the manufacturer’s repair process rather than treating a decorative craft guide as a repair specification.
Quick checklist
- Identify the plastic type
- Test for surface change
- Avoid flex lines
- Keep functional openings clear