Coating defect
Logo bridging
The film lifts out of an embossed logo or break line and spans across it, so the debossing goes shallow or disappears.
Written by the Rglax Pharma technical team, who formulate and manufacture every grade named on this guide at our WHO-GMP works in Tahliwal, Una (drug manufacturing licence NNZ/23/238). Reviewed 3 September 2026. Licences and certificates.
What usually sits behind it
- Film applied beyond the build-up the debossing can carry
- A film with high internal stress as it dries
- Shallow or steeply cut debossing on the punch
Worth knowing
An extra white grade reaches full cover at a lower build-up, so there is less film sitting over the logo by the time the core is hidden.
Every cause above is a process parameter, not a property of the material. If you are seeing logo bridging on a grade of ours, send us the run conditions and a retained sample and we will work back from them — start at the contact page.
Grades formulated against it
Where logo bridging is the problem the grade was made for
Aqueous film coat, extra white
Water base extra white film coat for cores that show through a standard white.
Aqueous extra white film coat developed for tablets where the core colour bleeds through a conventional white film. Calcium and Azithromycin cores are the usual cases. It gives higher opacity at the same build-up.
- Base ·
- Aqueous
- Finish ·
- Extra white, high opacity
- Formulated against ·
- Calcium, Azithromycin
Non-aqueous film coat, extra white
Solvent base extra white film coat for high opacity cover on sensitive cores.
Non-aqueous extra white film coat for moisture sensitive tablets that also need high opacity. It combines a solvent process with the covering power of the Wt10 series.
- Base ·
- Non-aqueous (solvent)
- Finish ·
- Extra white, high opacity
Read next
- Coating weight gain calculatorBridging is a coat built thicker than the engraving can carry.
- Picking and stickingTablets adhere to each other or to the pan, and fragments of film or core pull away, leaving pitted faces.
- Orange peel and roughnessA dimpled, matt surface rather than a smooth gloss, most visible under raking light.
- Colour variationShade differs tablet to tablet within a batch, or between batches that were meant to match.
- All 7 coating defectsThe whole list, with what each one looks like and the parameter behind it.