Numbers and sponsor logos flaking off a training set after one season is so common it is treated as normal. It is not.
What is actually happening
Applied ink or transfer needs a continuous surface to bond to. Open mesh does not have one; it has yarn and holes.
The decoration bridges the gaps, held only by the yarn it touches. Heat and agitation in a wash flex every one of those bridges, and they break along the holes. The result looks like a print failure and is a substrate failure.
The fix is a panel, not a better print
A solid knitted panel or yoke built into the garment gives a continuous surface. The same ink on the same machine now lasts, because it has something to hold on to.
The panel is part of the construction, which is why numbered and branded sets have to be specified before manufacture rather than printed afterwards.
What that changes about your artwork
Panels are read from a touchline, so the mark should carry heavier weights, fewer hairline elements and one or two colours. We redraw for the position free and show you both versions.
Numbers are sized to the distance rather than to the panel, and set in a single high-contrast colour. Outlined two-colour numbers close up visually at distance and become a blob.
When a patch is acceptable
A separately applied patch is better than printing on mesh and worse than a knitted panel: it adds an edge that can lift and it adds weight in one spot.
We use it where an existing set has to be updated rather than replaced, and we say what it will and will not survive.