Artwork Files for Bag Printing: AI, EPS, PDF, PNG—What Works?

Why artwork files decide whether your reward bag ships on time

Artwork is the first gate on a bag programme, and it is the gate most creators underestimate. Before a single panel is cut, someone has to convert your logo into something a screen, a heat press, an embroidery machine or a sublimation printer can reproduce five hundred times with the same result. If the file arrives as a 96 dpi PNG exported from a website, that conversion becomes a redraw, and a redraw is paid for twice: once in money and once in the three to seven working days it removes from a schedule that already runs 6-10 working days for sampling and 35-50 days for bulk production.

The commercial consequence is straightforward. A print-ready vector master lets a programme coordinator release artwork to the sample line on day one of the sampling window on any custom bag programme. A raster file of unknown origin triggers a technical query, and technical queries are the single largest source of avoidable delay in the pre-production phase because every unanswered day is a day added to the same clock. If you are still deciding which decoration route suits your reward, the print and embroidery options page maps each method to the file type it needs.

Minimum order quantity

500 pcs per style / colourway

Sampling

6-10 working days (12-15 for complex builds)

Bulk production

35-50 days after deposit + approved pre-production sample

Inspection

AQL 2.5 to ISO 2859-1

Trade term

FOB Xiamen

Payment

T/T 30/70

Production floor

4,950 m² SGS-verified, 137 staff, 7 lines, 149 machines

Monthly capacity

200,000 pcs per month

Artwork and programme contact

service@junyuanbags.com

Vector versus raster: what each decoration method actually needs

Vector artwork describes shapes as mathematical paths, so it scales from a 30 mm label to a 400 mm panel without losing edge quality. Raster artwork describes a grid of pixels at a fixed size, so enlarging it produces soft edges and stair-stepping on curves. That distinction is not academic on a bag programme: the same logo may appear as a 25 mm woven label, a 90 mm chest print and a 300 mm panel graphic, and only a vector master covers all three from one source file.

• Keep one master vector file as the source of truth and export derivatives from it rather than re-saving edits.
• Supply the working file, not a screenshot: an AI or EPS with layers intact lets adjustments be made without a redraw.
• If you only have a bitmap, expect a redraw charge and a delay of 1-3 working days before sampling begins.
• Ask for the traced vector back after a redraw so future re-orders reuse it at no additional cost.
• Store artwork at the largest plausible print size; you can always reduce, you cannot enlarge a raster cleanly.

AI, EPS, PDF, PNG and SVG compared for bag artwork

Adobe Illustrator (.ai) is the default master format in the bag industry because it preserves layers, colour separations and spot colour definitions in one file. EPS is the portable equivalent and is accepted everywhere, while a press-ready PDF carries the same vector data in a format that survives email, version-control systems and non-Adobe viewers. PNG has a legitimate role, but only as a raster output at final size with a transparent background, and SVG is usable in principle though still inconsistently handled by older cutting and embroidery software.

Two habits prevent most file problems. First, convert all text to outlines or paths before export, because a font that is not embedded will substitute silently and change your wordmark. Second, embed or package any linked raster images, because a missing link opens as a grey box in the production file. Where artwork is being prepared alongside fabric choice, the material customisation guide explains how coatings and weaves affect ink coverage.

Resolution rules by decoration method

Resolution only matters for raster processes, and the number that matters is 300 dpi measured at final print size, not at the size the file happens to open at. A 900 × 900 pixel logo is 300 dpi at 76 mm and only 100 dpi at 228 mm, which is why a file that printed beautifully on a small pouch can fail on a duffle panel. For vector processes, the equivalent rule is curve quality: a path traced automatically from a low-resolution bitmap produces wobbly edges and thousands of redundant anchor points.

Colour: Pantone, CMYK, RGB and why fabric moves the number

Spot colour is the language of screen printing. You nominate a Pantone reference, ink is mixed to that reference, and every unit in the run is printed with the same bucket. Process colour (CMYK) is the language of digital and sublimation printing, where four inks are laid down as dots to simulate a colour. RGB is a screen language and has no place in a production file, because an RGB value has no ink equivalent and will be converted unpredictably. The important caveat is that fabric is not paper: a Pantone matched on coated stock reads differently on 600D polyester than on 12 oz cotton canvas, because absorbency, weave texture and base colour all shift the result.

• Nominate Pantone references for every spot colour and state the coating system, for example Pantone TCX or a plastisol match.
• Limit a first campaign run to one or two spot colours; each additional colour adds a screen, an alignment step and cost.
• Treat a printed colour on a dark fabric as a two-stage job: an underbase white plus the colour, which changes the Pantone you should specify.
• Expect a tolerance: a shade tolerance of plus or minus one Pantone step is normal and should be written into the approval criteria.
• Approve against a physical strike-off, never against a monitor, and keep that strike-off as the bulk reference.
• For digital and sublimation work, convert artwork to CMYK with a known profile and supply a hardcopy proof for reference.

Colour also carries a compliance dimension when you sell into regulated markets. Dark dyes on polyester and certain pigment prints are the common triggers for restricted-substance testing, and our QA and QC process page sets out what is checked before a run is released at AQL 2.5 under ISO 2859-1.

Minimum line weights, text sizes and trapping limits

Every decoration method has a floor below which detail disappears, and the floor is set by physics rather than by preference. A screen cannot hold a hairline stroke because ink spreads into the weave; an embroidery needle cannot render a 2 mm letter because the thread is thicker than the letter; a cutting plotter cannot hold a 0.5 mm vinyl detail because it lifts during weeding. Design to the limit and the first strike-off passes. Design below it and you will be simplifying artwork after the sample has already been photographed for your campaign page.

Trapping is the compensating technique: where two colours meet, the lighter colour is extended slightly under the darker one so that a small registration shift does not open a white gap. Ask for it explicitly on multi-colour screen work. Placement tolerance belongs in the tech pack too — a logo placed 12 mm from a stated seam with a stated tolerance is measurable at inspection, whereas centred on the front panel is not, and unmeasurable specs are the ones that generate disputes when the run finishes.

What a print-ready artwork pack contains

An artwork pack is a small folder, not a single file. It should contain the vector master, a flattened PDF proof, the Pantone list, a placement drawing with dimensions, and a note of any legal markings. Sending all five means the first question you receive is a quotation rather than a clarification, which is worth several days across a programme that is already running 6-10 working days per sampling round.

1. Native vector master: AI or EPS, text converted to outlines, linked images embedded, artwork scaled to final print size.
2. Press-ready PDF proof: vector data intact, with a dimension line and a note of the Pantone references used.
3. Pantone list: every spot colour named, with the coating system and an acceptable tolerance stated.
4. Placement drawing: the panel, the measured distance from a named seam, and the print area in millimetres.
5. Method note: screen print, embroidery, transfer or sublimation, plus any special finish such as puff or metallic.
6. Compliance markings: fibre content, country of origin, care symbols and any required warnings for your destination market.
7. Version control: one file name, one version number, and a single named person authorised to approve changes.

From digital proof to strike-off to pre-production sample

Three approval artefacts exist on a bag programme and they are not interchangeable. A digital proof shows layout and proportions; it does not show ink behaviour on your fabric. A strike-off is the artwork printed on the actual production fabric with the actual method, and it is the only artefact that settles a colour question. The pre-production sample is a complete bag built from bulk materials and bulk decoration, and it is the unit the inspector measures against at AQL 2.5 before cargo is released.

• Approve layout from the digital proof within 24 hours; unresolved layout questions stop the sampling clock.
• Approve colour only from a physical strike-off on the production fabric in the production colourway.
• Keep the signed strike-off in a sealed envelope or a photographed, dated record; it is your reference if a dispute arises.
• Confirm the pre-production sample carries the final artwork version before you release the 30% deposit under T/T 30/70.
• Photograph decoration under consistent lighting if backers will compare units; camera flash exaggerates ink sheen differences.
• Record the decoration coordinates on the sample so the same placement can be verified during in-line quality control.

Artwork errors that cost calendar days on a campaign run

The delays below are the ones our production team sees repeatedly on crowdfunding programmes. None of them are caused by the artwork being ugly; all of them are caused by the artwork being ambiguous, incomplete or in the wrong format. Each one converts into working days because each one generates a query that must travel back to the creator and return before the next step can start.

Notice that the cheap errors are the early ones and the expensive one is the late one. An artwork mistake caught before the sample line starts costs a few days; the same mistake discovered after the run is sewn means rework, re-inspection and a delivery update to backers. That asymmetry is the whole argument for locking artwork during the sample prototyping stage rather than during bulk.

How artwork choices move unit cost, MOQ and re-order economics

Decoration is priced per colour, per placement and per method. A one-colour screen print on the front panel of a tote is the cheapest decorative option available at a 500 pcs minimum, while a three-colour print plus an embroidered logo plus a woven label on the same bag can add a meaningful percentage to unit cost and several days to the production window. The minimum of 500 pcs per style and colourway applies regardless, so the way to control cost is to control decoration complexity rather than to chase a smaller run — the low minimum production page explains how that minimum shapes a first campaign order.

The re-order argument matters more than most creators expect. Screen printing requires a film and a screen per colour; those are one-off costs that are already amortised on re-order, so a second run of the same artwork is cheaper per unit than the first. Embroidery digitising works the same way. This is why it pays to freeze the artwork at the first run and to hold the vector master in your own archive: it turns every subsequent re-order into a confirmation rather than a new development, and it keeps the 35-50 day bulk window from stretching at the front end.

Compliance markings and what belongs on the label

If your reward ships into the US or EU, the bag carries labelling obligations that exist independently of your branding. Fibre content, country of origin, care instructions and, for children's products, tracking information under CPSIA are typical requirements; REACH and Prop 65 govern substance disclosures, and EU GPSR adds product-identification duties. These markings need to be part of the artwork pack, because a legally required label added after bulk has started means a second decoration pass on finished goods.

• Decide early whether required markings sit on a sewn-in label, a printed neck tape or a hang tag, and include the artwork for all three.
• Set the text size to the smallest legible minimum for the chosen method, not to what looks good on screen.
• Confirm fibre content with your material choice before artwork is finalised; a late fabric change invalidates the label text.
• Keep warning text in the language of the destination market and check character support in the chosen decoration method.
• Ask for the label artwork to be quoted at the same time as the bag so the cost appears in the same RFQ.
• Retain the approved label artwork in your compliance file for the destination market.

Where artwork sits in the sampling and bulk calendar

Artwork is not a single event; it appears at four points in the programme. It is pre-flighted before sampling, applied to the sample, confirmed on the pre-production sample, and verified during in-line and pre-shipment inspection. Knowing which checkpoint you are at stops the most common scheduling error on campaign programmes: a creator approving a revision after the deposit has been released and expecting the production slot to be unaffected.

Once the checklist below is complete, send it with the tech pack, the quantity per colourway and the target delivery month and you will receive a quotation, a sampling estimate and a production window in one exchange. If you would rather have the files reviewed before you commit, request a quotation and attach the artwork pack to the same message.

The artwork checklist to paste into your RFQ

• Vector master supplied as AI or EPS, with all text converted to outlines and all linked images embedded.
• Press-ready PDF proof attached, with the final print dimensions noted in millimetres.
• Pantone references named for every spot colour, with the coating system and an agreed tolerance.
• Raster files, where required, supplied at 300 dpi at final print size with a transparent background.
• Placement drawing showing the panel, the measured distance from a named seam and the tolerance allowed.
• Decoration method stated per placement: screen print, embroidery, heat transfer, sublimation or woven label.
• Minimum stroke weight and text height checked against the limits for the chosen method.
• Compliance markings included: fibre content, origin, care symbols and any market-specific warnings.
• Version number on every file, with one named approver for the programme.
• Confirmation that the approved strike-off and pre-production sample become the inspection reference.

• Print and embroidery methods for custom bags
• Material customisation for Kickstarter bags
• Crowdfunding bag sample prototyping
• Kickstarter campaign bag QA and QC
• Custom bags for Kickstarter campaigns
• Low minimum bag production for creators
• Request a quotation

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