Support can make a sagging flap look fuller yet prevent the fastening from meeting naturally. The fold line, front panel and internal thickness work together; shape and closure cannot be assessed independently.
Record natural closure
With the bag empty, let the flap fall without pulling or pressing. Photograph front and side, noting fastening-centre alignment, left-right height and the fold line. Open only to its normal angle and inspect both sides for unusual creases, layer changes and old repairs.
Record a sunken flap, shifted fold and loose fastening separately. A loose component should not be compensated for by distorting the bag to bring the parts together.
Locate the affected layer
Soft surface leather, padding and internal support need different responses. A side view can help distinguish a local depression from a shifted whole fold, while concealed structural issues may need further assessment. A central depression with symmetric folds differs from the whole flap moving sideways; filling both completely may produce only a similar temporary appearance.
Change one condition
Where shaped support is appropriate, alter one position's amount and observe flap, walls and fastening together. Do not simultaneously fill, pull the flap and press the closure. Keep contact smooth to avoid new dents.
If closing requires marked pressure or stretching the front, undo the adjustment and reassess fold and space. Closing with force is not normal function. Unknown supports and finishes should not receive improvised heat.
Check empty and reasonably filled
Confirm that fastening halves meet naturally, opening is smooth and no new pulling occurs, first empty and then with reasonable contents within the design's use. Do not treat one model's support shape as universal.
Keep side photographs to show fold and internal-thickness relationships. Explain remaining limits imposed by the structure instead of selecting only the fullest-looking angle.
On a side photograph—not the leather—mark fold line, front-panel line and fastening. Repeat after changing support. A pushed-out front with an unchanged fold can increase the fastening gap; a shifted fold calls for a connection and structure check.
Compare REBIRTH's Chanel CF reshaping and Le Boy flap-sagging lessons, recording each fold, closure and support position. Understanding why the two cases differ is the transferable skill.