A two-tone thong sandal is one of the easiest summer SKUs to sell and one of the easiest to get wrong on a repeat order. The footbed sits in one colour, the strap and outsole trim sit in another, and every size in between has to arrive in the proportions your shelves and your marketplace listings actually need. That is why experienced buyers do not simply reorder "the same item": they ask the factory to lock the size run, the colour split and the inner pack before a single pair goes back on the line. Below is how to structure that request when you work with an EVA foam products manufacturer, using our own two-tone thong tooling as the worked example.

What "locking in the case pack" actually means for a two-tone sandal

For moulded EVA thong sandals, three separate decisions get bundled into one sentence in most purchase orders. Split them out and you can put each one in writing.

• Size run. The ratio of pairs across the sizes in a range, for example how many pairs of each length sit inside one assortment. Our thong flip-flop tooling covers adult sizes and children's sizes, so state which band you are reordering and whether the same split applies to both.
• Colour split. How many pairs per colourway in each size band. On a two-tone model the "colour" is really a combination: footbed colour plus strap and trim colour, so list the combinations by name rather than by single colour.
• Inner pack and case build. How pairs are bagged and how many pairs sit in a shipping carton. On our published disposable EVA slipper specification, each pair goes in an OPP bag with cartons of 200 pairs, and 12 pairs per pack is listed as an alternative; for moulded thong sandals the carton count is set with you rather than fixed by us.

Ask for all three in one line item on the follow-up purchase order, not in a chat message. A written case-pack specification is what your receiving team checks against and what your supplier's packing list references.

Why two-tone uppers make the repeat order riskier than a solid colour

A plain single-colour sandal can absorb a small mismatch: if one size comes slightly short, you still have a sellable unit. A two-tone model cannot.

• Two colour decisions per pair. Our published two-tone thong specification pairs a white footbed with a coloured strap and outsole trim, listed in red, blue or green. That means three strap-and-trim variants to schedule on a re-run, and each variant needs its own size split. A shortage in one variant strands the matching sizes of the others.
• Colour is formed at foaming, not afterwards. We colour EVA in a one-step foaming process with added colour masterbatch, so footbed and trim colours are set when the batch runs. Once the foam is out, changing a mix mid-run is not a quick adjustment. Locking the split before production protects both sides.
• Contrast shows drift. Where a light footbed meets a dark strap and trim, small colour differences are visible on the shelf. Tell us your destination country up front so we can match raw materials to the standards that apply there, and confirm the colour reference on the signed sample rather than on a digital proof.

The five items to put in writing before the follow-up order

This is the shortlist we ask our own footwear and promotional-goods buyers to confirm. Anything missing here tends to resurface as a change request during production.

How our own process handles a repeat run

Because we mould and print in our own Shenzhen factory, a follow-up order normally reuses tooling you already paid for. The steps below are the ones that touch your case pack.

• Design review. We check your drawings or previous samples and flag changes that affect packing, such as a new strap material or a thicker footbed that changes carton volume. Our custom work is produced by stamping and laser cutting from customer drawings or samples.
• Proposal and quotation. The case-pack structure appears here, together with the tooling position from your first order.
• Drafts and print plates. Where a printed logo or graphic sits on the two-tone upper, this is the point to reconfirm the artwork against the colour combination.
• Moulding and printing. We use self-developed heat-transfer printing with multi-pass white-base printing for saturation, which matters most when a bright graphic sits on a coloured footbed.
• Sign-off and deposit. A 30% deposit is due on signing the contract. Plate-making runs in 5–7 days and bulk delivery is quoted at within 15 days; product pages that publish a production lead time separately state 25–30 working days from sample confirmation, so confirm the window for your artwork and quantity before you commit to a delivery date.

On quality, products go through our in-line testing programme during production, and we support 100% third-party inspection as well as audits you run yourself. If your receiving team checks case packs against a written specification, that same document becomes the basis for the pre-shipment check.

What to do when the first order's size mix underperformed

This is the most common reason a distributor wants the case pack changed on a follow-up, and it is easy to fix if you raise it before the run starts.

• ｒｅｎａｍｅ the assortment, do not just say "change sizes". Give the new split per colourway. A two-line table in your email is enough.
• Ask for single-size cartons on the slow sizes. Mixed cartons force you to open cases to replenish one size. Single-size cases cost a little more in packing and save labour at your end.
• Keep one colourway stable. If you are testing new colours, keep the proven combination on the same case pack as before so you can compare sell-through fairly.
• Do not change strap material and size run in the same order. Our flip-flop listings describe both braided textured straps and plain ones, and a textured strap sits differently on the foot. Change one variable at a time if you want clean sell-through data.

A worked example: our two-tone thong line

Take the two-tone EVA flip flops we list as classic summer beach thong sandals for men and women. The published build is a white footbed with a textured strap and outsole trim in red, blue or green, an embossed anti-slip grain on the footbed, and a flat sole in adult unisex sizing across multiple sizes.

A sensible follow-up request against that model reads like this: three colourways; size run stated as pairs per size for each colourway; one pair per OPP bag; cartons built single-size for the two slowest sizes and mixed for the rest; footbed logo carried forward from the approved sample; and rejection criteria for strap-colour mismatch agreed before production. That single paragraph removes most of the arguments that appear after a container arrives.

If your assortment also needs children's sizes, say so in the same request. Our thong flip-flop tooling is offered in adult and children's sizes, but the two bands need separate size runs — a ratio that works for adults does not fit a kids' shelf.

Related models worth putting in the same container

Distributors often consolidate a follow-up sandal order with adjacent SKUs to fill the container. On our catalogue these sit close by:

• Solid colour EVA flip flops — solid-colour sole with a PVC, rubber or fabric strap in colours such as black, navy, yellow and pink, quick-drying and water-friendly, useful as the anchor SKU behind a two-tone promotion.
• Men's classic anti-slip beach thong sandals — braided textured strap with a wave-grain footbed, listed in solid black and in teal with black trim.
• Promotional flip flops — for branded giveaway programmes where the logo is the point of sale rather than the colourway.
• Disposable EVA pedicure slippers — a one-size consumable for salons and spas, useful when you want a fast-moving companion SKU in the same container.

Questions to send your supplier before you reorder

• Can you reproduce my previous size run exactly, and what is the smallest change you will accept per colourway?
• Which colours are already foamed in your standard palette, so a repeat run avoids new material lead time?
• Will my approved sample be kept on file and used as the colour reference for this run?
• What is the packing list format, and will it show pairs per size per carton?
• Which inspection reports and test documentation come with the shipment for my market?

If you want a second opinion on an existing case pack before your next order, send us the packing list from the last container together with your sell-through by size. We will tell you what can be changed on the current tooling and what would need new work.