Artwork and Dielines for Custom Mylar Bags: A Checklist Before You Print

Before a pouch is printed, it is drawn as a flat outline: the dieline. It carries the finished dimensions, the fold and seal areas, the zipper position and the layered panels of a stand-up pouch. Every layout question is settled there, cheaply — and every one that is not gets discovered on a pallet.

What the dieline actually contains

• Finished dimensions — width, height, gusset depth. The number your size is quoted from.
• Seal areas — the margins at the sides and top that are heat-sealed. Nothing important can live there: no text, no logo, no QR code.
• Fold lines — where the pouch forms its base and, on a stand-up pouch, where the gusset opens.
• Zipper position — the closure sits at a specific height, and it will sit over whatever is printed beneath it.
• Panels — a stand-up pouch is more than one surface: front, back, two sides, base and the inner fold. Artwork for each.
• Cut and score marks — tear notches, hang holes, windows, die-cut outlines.

We generate the dieline free with your quote, drawn to the exact size you order. Send it to your designer, or send us a sketch or logo and our design service lays out the panels for you.

Bleed and safe areas

Two numbers decide how much of your design survives the machine:

• Bleed — extend background colour and images past the cut line, typically by 3 mm, so slight cutting movement leaves no white edge.
• Safe area — keep text, logos and anything with meaning well inside the seal and cut lines, typically 3–5 mm clear.

Where a design fails: a background that stops exactly at the cut line (white slivers on some pouches), and a legal statement placed close to the bottom seal (partly sealed over). Both are fixed in five minutes on the dieline and cost a full reprint if they are not.

Designing for panels, not for a flat rectangle

A pouch is not a poster. When it fills, the flat artwork curves over a three-dimensional shape, the base folds under, and the side gussets compress.

• Front — brand, product name, weight. Assume the sides of the panel bend away from view.
• Back — the practical panel: ingredients, warnings, batch field, contact details, barcode.
• Gussets — narrow strips. Use them for pattern, not for information.
• Base — printable, and the panel most brands forget until they want it.

Print is full colour, front and back, so the only limit is how you lay it out.

Colour: what matches and what only comes close

Brand colours are usually specified as Pantone. Print comes back as CMYK process, spot colours or a combination, and the achievable result depends on the substrate — a matte or metallised film reads differently from paper. Practical guidance:

• Send brand colours as Pantone references, not as hex codes from a screen.
• Expect close, not identical. Deep blues, vivid greens and metallics on film are the usual drift points.
• Metallised film changes colour: artwork printed over a reflective layer looks different from the same artwork on white film. If you want the metal to show through, design for it deliberately.
• White underprint matters. On metallised or foil pouches, colours need an opaque white base layer or they will look darker and shifted.
• Ask for a proof on the actual film if the colour is critical to the brand.

File checklist before you send

Item	What we need
Format	Layered file (AI, PDF or PSD) at print size — not a compressed JPEG
Resolution	300 dpi at 100% size for any raster element
Colour	CMYK or Pantone references, with brand colours listed
Bleed	3 mm past every cut line
Marks	Keep the dieline layer separate and switched off in the print version
Fonts	Outlined, or embedded in the PDF
Text	Minimum legible size on film — very small hairlines and reverse text fill in faster on film than on paper
Variable data	Batch, lot and QR fields as separate layers if they change per run

Proof, then bulk — in that order

On every custom job we produce a finished pouch for you to approve: size, film, finish, colour and closure, exactly as it will run. That is the moment to change things, because after approval the pouches are printed, laminated, cured and sealed, and the material is committed.

Two practical notes on approving a physical pouch:

• Judge colour under daylight, not under office lighting, and compare it with your brand guideline side by side.
• Check function as well as looks: seal it, open the zipper, and fill it with your product. A pouch that passes visually can still fail in the hand.

How the artwork stage fits the schedule

Artwork approval is the gate the whole project waits on. Production is about 3–10 days after approval, and in practice the design stage takes longer than the print stage. Two things keep it short: send print-ready files rather than a logo dropped into a screenshot, and nominate one person to sign off rather than collecting opinions.

If the artwork is the reason for your delay, our design service lays out every panel from a sketch or logo at no charge — see what to ask a supplier for the other questions worth settling early.

Sources and standards

Primary sources for the rules and test methods referred to in this guide:

• Pantone colour systems — brand colour references (Pantone)