Ink notes
Substrate Check
A practical press-floor note on checking film, board and other substrates before ink goes down on a packaging run.
Many print faults begin before ink reaches the press, with the wrong film, board, or treated surface loaded for the job. Substrate Check covers the material checks that matter on South African flexo packaging work.
Substrate Check is written for the moment before ink is mixed and stock is mounted. On South African flexo work, the first review is the roll, sheet or stack itself, looking for wrong grade, poor storage marks, edge damage and treatment issues.
Roll labels and stock identity
- Job number matches roll tag
- Outer wraps checked for tears, damp and dirt
- Film type, gauge or board grade confirmed against the job card
- Mill or converter details recorded exactly as marked
Here the focus is substrate condition before print starts, not ink strength or plate choice. Used properly, it helps the crew stop a stock error before metres are wasted.
Before ink meets the web
Substrate Check covers the inspection done before ink touches film, board or another packaging material. A quick check for surface condition, damage, mix-ups and roll labelling can prevent a costly run from starting on the wrong stock.
Start with the material specification and the storage history of that batch. A PE film from a humid Durban store can behave differently from stock kept inland near Johannesburg, especially where surface treatment and static are concerned. The page is aimed at day-to-day flexo packaging checks, not laboratory testing.
Look at the first accessible section, not only the outside label. Creases near the core, crushed roll edges, blocking on film and board corner damage can all appear before the pressman notices a print defect. Catching those signs early protects ink, plates and press time.
Checks that stop wrong stock
A proper substrate check gives the operator a clear go or hold decision before setup continues. The useful record is simple: what material arrived, what condition it is in, and whether it matches the packaging specification. Good notes here support traceability when waste, adhesion or colour complaints are investigated later.
Use Substrate Check with the related press notes when a repeat job suddenly behaves differently. Before a reel goes onto the unwind, compare the docket, roll marking, width, treatment status and any visible damage with the job sheet. Name your press and the job on it, and we will put together the consumables for the run.
- Width and repeat suit the press
- Surface viewed before splicing or mounting
- Observations logged for the shift
South African handling conditions
Material condition can change between dispatch, warehousing and press loading. Inland dust around Gauteng sites may contaminate exposed rolls, while coastal moisture in KZN can affect paper and board stability during storage. Export and retail packaging work both benefit from tighter stock identification when several similar substrates are on hand.
Cold mornings can stiffen some films and make edge handling less forgiving. Heat in the converting area may worsen telescoping, blocking or liner movement if rolls were stored badly. Power interruptions also matter because part-used material may stand uncovered longer than planned.
Operated by Astros Marketing (Pty) Ltd from 2 Makro Place, Sunnyrock 1401.
Inspection points on film and board
A practical press-floor note on checking film, board and other substrates before ink goes down on a packaging run.
Keep the entry tied to the same job record used for inks, plates and press settings. That makes later tracing easier when the issue turns out to be the substrate batch rather than the anilox, doctor blade or impression setting.