My Wick Supplier Changed the Tab but Says the Wick Itself Is Identical — Should I Still Check End-Of-Life Candle Behaviour?

What the tab does — and why “the wick is identical” is not the whole answer

A wick tab — sometimes called a sustainer — is the small metal disc crimped onto the bottom of the wick. It does three jobs. It anchors the wick to the base of the jar so it stays upright while you pour and while the pool is liquid. Its neck, the crimped collar that grips the wick, sets the point below which the wick cannot draw fuel, so it decides where the flame starves and goes out. And its size and weight affect how steadily it sits — how well it stays put on a wick sticker when the wax around it is molten in the last burn. None of those three jobs happens during the first nine-tenths of the candle's life. All of them happen at the end.

So a supplier can be entirely truthful that the wick itself — the braid, the core, any coating — is unchanged, and the candle can still behave differently at the bottom of the jar. A taller neck leaves more wax behind when the flame goes out. A shorter neck, or a tab that lets the wick burn lower, brings the flame closer to the glass base in the final minutes. A lighter or smaller disc, or a different finish, can change how well it holds to your sticker once the wax around it is liquid. These are general mechanisms, commonly described; they are not measurements, and CSI publishes no tab height, tab type or construction detail for its Eco, Cotton Braided or Wooden wicks either. That is why the answer to the title is yes, and why the check is aimed at the end.

The retest matrix for a tab-only change

If you accept the supplier's statement that the wick above the tab is identical, most of the candle's early behaviour should match. Accept it provisionally — confirm it with a short side-by-side — and put your real effort where the tab acts.

Step one: inspect and measure the tabs themselves

Before you pour anything, put ten old-tab wicks and ten new-tab wicks side by side and measure them. This costs nothing but time, and it often tells you what to look for in the burn test. Use a ruler or callipers and your scale; check what resolution your scale reads to before you trust a small difference. None of these figures is published for any CSI wick, so the only numbers here are the ones you take.

If the neck height is visibly different, the leftover-wax question in the tab-height post applies directly, and that post shows how to turn a millimetre difference into grams of wax and hours of burn. If the disc is different but the neck is not, your main risks are sitting, centring and tab lifting. Either way, write the measurements down: they become part of the wick's specification on your formula card. And ask the supplier in writing exactly what changed — tab source, material, neck height, crimp. CSI does not publish change notices for its own wicks, so for any supplier, your measurements are the record.

Step two: the end-of-life test

The design uses two kinds of candle. Shallow-pour candles hold only 60 g — 55.2 g of wax and 4.8 g of oil at 8% — so the flame reaches the tab after a burn or two. They are a working practice for screening tab behaviour quickly: extinction point, leftover wax, tab lifting. They do not reproduce the heat the glass builds up over a full candle's life, so they cannot stand alone. The full-height pair — one old tab, one new, 200 g each — runs the whole life and shows the last burn as a customer would see it. One retained, unburned control completes the set.

No fragrance ceiling is published in this data for Premium Coconut Soy Wax CSI 468, so 8% is used here only as a labelled test load inside the 6–10% range makers commonly start from; check the product page or ask CSI on WhatsApp for the wax maker's stated maximum before you set a production load. The shallow fill is also a working choice: weigh what your jar holds at the level you pour, and use the same weight for every shallow candle.

Two sibling tests share this page's logic. If the new tab also comes with a smaller flame, the full-height pair doubles as the full-life check in the smaller-flame post. If the final burn looks hotter, stop and apply the hotter-jar rule — no benefit is traded for heat. The same end-of-life questions arise when the jar base changes rather than the tab, as the thicker-base jar post explains, and if an order is waiting, the emergency-order post shows how to fit this test into a tight schedule.

The end-of-life scoring sheet

The leftover line is the only one expressed in grams, so it is worth seeing how the weighing works. If a jar with its wick and sticker weighs an example 262.0 g before pouring and 270.5 g after the flame has gone out for the last time, the leftover is 8.5 g — 4.6% of the 184 g of wax a 200 g candle holds at 8%. The example figures are there to show the arithmetic, not a result; compare your old-tab and new-tab averages, not single candles.

The decision rule

The last row is the one people read as good news. Less wax left sounds like more candle for the customer, but it usually means the flame burned closer to the glass base, which is exactly where the heat risk sits. A lower finish is acceptable only if the last-burn flame and base lines are no worse than the old tab. CSI publishes no numeric base-temperature limit; the line is your approved control, your jar supplier's guidance and the fire-safety standard you work to.

The priced end-of-life kit

All items are listed, in-stock CSI sizes on the pull dates, with a 5% pour-loss allowance (working assumption). The wicks are your own — the old-tab stock and the new-tab delivery — so they are not priced. Wick stickers and the scale are listed separately because many makers already have them.

Release and record

If the leftover wax is clearly higher with the new tab, the next question is what that costs you in wax, oil, burn hours and label claims: the tab-height post does that arithmetic. If the whole wick has changed, not just the tab, start from the same-length-and-thickness post and the master checklist.

Frequently asked questions