What an art supply shop should ask a platform vendor before signing

A twelve-tube watercolour set contains tubes you also sell singly. If the platform stores the set and each tube as separate stock figures, you will oversell one or the other inside a week.

Watch the vendor build a bundle from components, then sell one set and one loose tube and read both stock counts afterwards. The set should vanish from the shop when any tube it needs runs out, and return when a delivery arrives. Otherwise you will fix counts by hand.

Probe the awkward cases: a gift box holding three brush sizes, a pad sold with a pencil case, a starter kit that swaps one component. Substitutions should be a setting. They should never need a developer.

Art buyers search in the trade’s own words: cadmium red, burnt sienna, 2B, cold pressed, rough, round size six, sable or synthetic. A platform with only title, colour and size fields cannot filter on any of these, so every search ends in a scroll.

Ask to add custom fields live. Try pigment code, series, opacity, paper surface, paper weight in gsm, pencil grade, brush shape and canvas depth, one after another. Each must become a filter on the category page. It must also appear as a column in the export file.

Then test a variation: one paint, thirty shades, three tube sizes. The vendor should show how that is entered without ninety separate pages, and how a shopper picks a shade from a swatch image.

Aerosol fixatives, spray varnishes, turpentine and white spirit are often classed as flammable for transport, and carriers refuse many such goods by air or to some destinations. Craft blades can carry age rules too.

Ask whether a flag on the product can restrict shipping methods, destination countries and customer type, and whether it blocks checkout or only warns. Ask where the safety data sheet attaches. Some buyers and carriers request it.

Test with a real basket: one can of spray varnish and one pad of paper, sent by air to an island address. The platform should split the parcel or refuse the line, with a message the customer can follow without phoning you. Confirm the rules with your own carrier.

A customer wants a canvas sixty by ninety centimetres on a deep stretcher bar, cut and stretched only after the order. That is a made-to-order job, not a catalogue item.

Ask for width and height inputs with minimum and maximum values, and a price that follows size bands or a formula. Each choice, from primed or raw to cotton or linen, belongs in a field. The order should reach your workshop as a cutting list with exact dimensions, not as a line of free text.

Made-to-size lines should carry their own lead time and return terms, and the stock of canvas rolls and stretcher bars should fall when a job is cut. Otherwise a roll runs out unnoticed.

Art schools and studios order by list. They pay against a purchase order. Ask for a quotation built from item codes, with a customer price list, a validity date and the purchase order number carried onto the invoice.

Before signing, ask the leaving questions. Can you export products, variations, customers and order history as CSV? Who owns the product images and descriptions? What happens to your web address when the contract ends? Get the answers in writing.

Finally, send the vendor your three most awkward real orders and ask for a recorded run-through in a demo store. Score each answer against what was promised on the call.