>>> Very nice forum here. I have a pair of nearly new shell cordovan loafers made by Crockett & Jones. They are made of medium brown leather from Horween.
Cordovan is leather made from the fibrous flat muscle (or shell) beneath the hide on the rump of a horse.
>>> One morning I noticed a spot the size of an American nickel on the top of one shoe. I don't know what it is from. Could be a bit of urine, food oil, or who knows what.
Picture looks like a penetrate stain most probably from oil related. Urine stains would show a shower of fine dots and may be detected by smell by now.
>>> I have about 30 pairs of Alden shell shoes, so I am very familiar with this leather. I tried the usual approach of a bit of water and brushing like mad. No effect at all. I have Venetian shoe cream (recommended by Horween) and Saphir Renovateur, but haven't used either on the spot.
Leather is an amphoteric protein fiber and is sensitive to pH fluctuation especially if they are absorbent. Recommend to use leather-safe products with a pH range of 3 to 5. Neutral to alkaline solutions will show signs of darkening effect as the light colored leather sometimes behaves like litmus paper.
>>> The shell cordovan leather seems to be finished slightly differently on the C&J shoes compared to my Aldens. The surface seems smoother and waxier; so perhaps the water didn't penetrate and reach the leather.
Aniline leather may comes with its fashion varieties like: Pure Aniline, Wax Aniline, Gloss Aniline, Satin Aniline, Wax Pull-up and Oil Pull-up. Aniline means that the dyestuff used are transparent and the pull-up fashion effect of oil or wax, toppings or topcoats differentiate them.
Note:
Besides the irregular shape dark stain could be a possibility of oil, grease and alkaline derive source, there is also residues perhaps from ageing solid conditioner that need to be stripped off at the same time. The leather has to be clean as a whole and not just the spot for a more even appearance, especially on absorbent leathers may appears like an iceberg more beneath the surface that will take more than one time to wick them up. Perhaps it is more effectively by a “reverse technique” to be trapped by a stretchable paper towel than still remaining on the leather surface when dry (technique practice by the Leather Doctor system).
>>> Recommendations please.
This Aniline (A) Leather Problem Solving Guide may be used as reference. Since this is a light duty leather, AnilineTop-21G for gloss or S for satin is recommended to used instead.
To be continue. . .
Roger Koh
Leather Care Consultant
www.LeatherDoctor.com