The number to watch
Credit outstanding at the end of the finishing season. Putty and finishing material go out in bursts when sites reach completion, and the credit goes out with them. The figure that matters is not the season's sales but what is still owed a month after the season ended, broken down by age. Shops that look at that number and set limits before the next cycle carry far less into the following year than shops that only look at turnover.
Pack size and brand are the item
A 40kg bag and a 20kg bag of the same putty are different items with different rates per kilo, and a painter buying both will notice if the arithmetic is wrong. Holding brand and pack size on the item means the rate is right and the stock figure counts bags rather than an abstract quantity — which is what you actually have in the godown.
Demand arrives in bursts
Finishing material does not sell steadily; it sells when sites reach the finishing stage, which clusters. A shop that orders on last month's figures runs out in exactly the week it matters. Movement reports over a longer period, with low-stock alerts on the fast brands, turn ordering into a decision based on figures rather than on what the last customer asked for.
Painter and contractor credit
Your regular buyer draws material through a job and settles when the owner pays him, so credit runs for the length of the site. That needs a limit set at the start rather than after, ageing so you can see which jobs have stalled, and a statement each month. Because the amounts per visit are small and frequent, this is a trade where the ledger keeping itself from the billing matters more than usual — nobody is going to enter forty small credit sales twice.