The most common defects in wall tiles are print faults, shade differences, size and calibre variation, warpage, chipped edges, glaze faults such as pinholes, and crazing. Most can be caught before loading if someone checks the boxes against the sample.
Some defects are allowed within a grade, so the first step is a written grade definition from the factory. Our guide on Premium, Standard and Commercial grades explains how grades work.
Surface and print defects
- Print lines: a blocked inkjet nozzle leaves a fine line along the tile, often along a whole run.
- Colour drop-out or banding: patches where one ink colour is weak or missing.
- Pinholes: small holes in the glaze, from gas escaping during firing or dust on the surface.
- Crawling: glaze that pulls back from an area and leaves a bare patch.
- Spots and specks: dust, kiln debris or glaze drops fired into the surface.
- Effect glaze faults: uneven metallic or glitter areas on decor tiles.
Shape and size defects
- Warpage: tiles that bow at the centre or curl at the edges, which leaves uneven joints on the wall.
- Size variation: tiles in one box that differ in length or width, giving wavy grout lines.
- Out of square: corners that are not at right angles.
- Chipped edges and corners: from handling on the line or poor packing.
- Cracks: fine cracks through the body, sometimes visible only when the tile is tapped or held to light.
Warpage is easy to check with a straightedge, as shown in how to check wall tiles for warpage.
Defects that appear later
Some faults do not show at the factory. Crazing, a web of fine cracks in the glaze, can appear months after fixing as the porous body takes up moisture. The test is explained in crazing in wall tiles.
Shade differences between batches also show up later, when a customer needs more tiles and the new boxes do not match. Keep batch records and some spare stock from each batch.
Defects from mixing
Some complaints are not tile faults at all but sorting faults. Two shades or two calibres in one order, or a lower grade mixed into Premium boxes, cause problems on the wall even when each tile is fine. The fix is a purchase order that fixes one batch, one shade and one calibre per design, and a check of the box codes at loading.
How to catch defects before loading
- Agree a written grade definition with allowed defects per box.
- Inspect a sample of boxes from each design, chosen at random from the stack.
- Lay tiles out on a board or wall, at a normal viewing distance and under good light.
- Check shade, batch and calibre markings on every box against the packing list.
- Keep photographs and retained samples from each batch.
Next step
We inspect wall tiles at the factory, lay them out against the approved sample and stop loading if the boxes do not match. To set up inspection, book a free sourcing review.