Hello,
The cracks on your leatherette sofa are most likely due to a build-up of sebum deposited by contact with the neck and hair, together with a lack of maintenance (cleaning + varnish).
Repairing the cracks on your leatherette sofa is in principle still possible. Leatherette is a flexible plastic material that is less easy to repair than leather.
First of all, we advise you to get a neoprene-type glue, which will allow you to press back down the flaps of material that are coming away from the fabric backing.
Then apply our black RépaSkaï to fill the cracks, following the instructions supplied with the product.
Once these steps are complete, clean your sofa with our leatherette cleaner/stain remover/degreaser.
You will then need to recolour it to hide the repairs, using our leatherette sofa paint.
Please note that if you are demanding, we strongly advise against recolouring only the repaired area. You will certainly end up with an uneven colour.
Finally, you should protect your sofa with a protective varnish.