In my search for care for my beautiful new vaja case, I found this on a Vaja site:
PROPER LEATHER; MAINTENANCE & CLEANING
One a week, polish the leather with dry and clean cloth or soft and mild brush. With this minimal care your leather product will provide long- lasting use. We recommend using a natural cream. (Eg: Meltonian). Sparingly applied with a soft clean cloth and then brushing the polish immediately after.
GENERAL INDICATIONS
1/Do not put adhesive sticker, glue will permanently mark the case surface.
2/Do not over- stuff credit cards slots or money pockets. Doing so will stretch the leather.
3/Leather breathes, that is what keeps, is soft and supple. Do not store the case in plastic bags. Cover your leather with breathable cloth like cotton sheets when storing.
-Hereby we will provide some suggestions (though they should not be considered as solutions) about how to proceed in some common situations that may occur.
NOTE: If these procedures do not work for you, consult a professional leather care expert. Vaja will not assume any responsibility for damage incurred by owners based on information provided here.
Water
If they are only drops, press firmly with absorbent paper on the surface and then let them dry in the shade. Please do not apply completely dry, rub the surface with a clean and dry cloth to restore the shine.
If your case becomes wet, as fast, as you can, take an absorbent paper and soak up, do not rub just blot. Allow it to dry slowly and naturally at room temperature, avoiding direct heat: hot air vents, radiators, furnaces, Air dryers, or sunlight. When leather is dry, apply a little uncolored leather polish
(Eg: Meltonian), on it to restore flexibility. This can help, but unfortunately your case never will look the same.
Oil
For butter, oil, or grease, wipe excess butter oil or grease off the leather with absorbent paper and then leave it alone as the spot should dissipate into the leather in time. Do not apply water to try to wash, a butter, oil or grease spot.
Ink
Do not wet the stain or apply, solvent alcohol, or water. With a clean, white and soft pencil eraser, press softly erasing the pen stain. Follow the procedure again if necessary. Then rub with a cloth or an extremely soft brush to remove the remaining rubber. If necessary, apply only uncolored leather polish over the area. Let it dry and rub with a dry cloth to restore shine. In vaja leathers this procedure helps to diminish the stain and according to the leather tone itself, it can even disappear completely. Do not try to use this procedure to remove ink stains in Aniline leathers, these leathers have no protective treatments applied to them, the stain is likely to remain. Do not try to remove it with our suggestions or your own method. Leave the stain, within a few months. Aniline leathers will darken slightly and begin to develop a rich patina.
Scratch marks
Scratch- marks simply, do not go away, and tend to get bigger with use. However, if it does happen, you could try using some uncolored leather polish (Eg.Meltonian) to cover the scratch. If it is small, this might repair it or at least hide it, but otherwise it is there for good.