Custom Mylar Seed Bags
Custom mylar seed bags from 100 — flat pouches and small stand-up bags for garden and microgreen seed, with a barrier that keeps the seed dry and dark, a zipper the gardener can close again in May, and a back panel with room for sowing instructions.
Seed is alive in the packet, and it is counting the humid days
- Film
- Three-layer mylar laminate, foil or metallized core, 3.5–5 mil; clear-front option
- Formats
- Flat three-side-seal pouch, flat zipper pouch, small stand-up pouch
- Fill weights
- 1 g packets to 1 lb stand-up bags
Get a price for Mylar Seed Bags
Send the size and quantity — we reply the same working day with a price, a dieline and a date. Artwork optional at this stage.
- Free dielineThe flat drawing comes with the quote, before you commit.
- Proof before pressNothing is printed until you have seen it laid on the dieline.
- Die kept for reordersTooling is paid once. Every reorder skips straight to press.
- Quoted in four marketsUS, UK, Canada and Australia, in the delivery currency.
What a seed bag has to keep out
Two things shorten the life of seed in a packet: water vapor and light. Vapor is the worse of the two, because seed is hygroscopic and pulls moisture from the air until it matches the room. The laminate we use for seed is a three-layer film with a foil or metallized center, which cuts vapor transmission to a fraction of what kraft paper allows. Light matters less for most vegetable seed but does for some flower seed, and a foil bag blocks it completely while a clear-window bag blocks it everywhere except the window.
The window is a trade. Customers like to see the seed, especially for beans, peas and corn where the seed itself is part of the appeal. For fine seed like lettuce or basil, a window shows a pinch of dust at the bottom of a bag, so we usually print the plant on the front instead.
Two formats, and the quantity that decides
| Flat three-side-seal pouch | A packet-sized sachet for 1–20 grams; heat-sealed at the top after filling |
|---|---|
| Flat pouch with zipper | Same size with a press zipper under a tear notch, for seed sold in more than one sowing |
| Small stand-up pouch | Bottom gusset, zipper and optional window, for 50–500 grams of beans, corn or cover crop |
| Clear-front, foil-back pouch | Shows large seed, keeps the back wall as a full barrier and a print surface |
A tear notch above the zipper lets the first opening be clean without scissors. We cut it on every zipper pouch unless asked not to.
The printed panel does most of the work
- Front: common name, variety, a picture of the plant or the harvest, and the packed-for year.
- Back: days to germination, sowing depth, spacing, sun, and a sow-by month or a lot number.
- A blank or lightly tinted box for a hand-stamped lot number and seed count.
- Germination percentage and test date where the seller publishes them.
- A small line that says keep cool and dry, because a mylar bag only helps while it is closed.
Filling and sealing on a bench or a line
Most seed sellers fill by hand or on a small volumetric filler, and a flat pouch suits that: it lies open, takes a scoop, and seals on a hand impulse sealer in a second. We supply flat pouches open at the top with the three other sides sealed. Stand-up pouches come with the zipper fitted and the top open the same way. For a line with a form-fill-seal machine we can supply the same laminate on a roll instead, printed in register.
The seal is only as good as the surface it closes on. Seed dust in the seal area is the usual cause of a leak, so we leave a seal band clear of print and recommend a quick tap of the pouch before it goes into the sealer. If you also sell seed in a printed carton, our plantable seed paper boxes are a different product with a different purpose, and the two are often paired at a market stall.
Microgreen and sprouting seed in larger pouches
Microgreen growers buy seed by the quarter pound and the pound, which is a stand-up pouch rather than a packet. Those bags take a wider zipper, a bottom gusset deep enough to stand when half empty, and a label area for the sprouting instructions that growers actually read: soak time, blackout days, harvest day. Sunflower and pea seed are large and heavy, so the gusset is cut from the same laminate rather than a thinner film, and the side seals are widened to hold the weight when the bag is picked up by its top.
Mylar Seed Bags — specification
The rows that are specific to this build first, then what applies to every job we run. Anything not listed is a question, not a limit — send the brief.
This build
- Film
- Three-layer mylar laminate, foil or metallized core, 3.5–5 mil; clear-front option
- Formats
- Flat three-side-seal pouch, flat zipper pouch, small stand-up pouch
- Fill weights
- 1 g packets to 1 lb stand-up bags
- Closure
- Heat seal; press zipper with tear notch on resealable formats
- Window
- Optional clear panel on the front wall
- Full color on front and back, matte or gloss; blank lot-number box
- Food contact
- Film suitable for seed and dry food
- Minimum
- 100 pouches per size and design
On every job
- Print process
- Flexo in up to ten colors on the outer film, or digital for short runs and changing artwork.
- Color
- A white underprint carries normal color on metalized or clear film. Without it, every color takes on what is beneath it.
- Tolerance
- Bag width plus or minus 2 mm, length plus or minus 3 mm. Film stretches, so a barcode is verified on a filled bag.
- Tooling
- Print plates or cylinders per design, kept. There is no cutting die — the bag is formed and sealed rather than cut.
- Food contact
- A food-grade sealing layer against the product, with the inks trapped between layers rather than on the food face.
- Sustainability
- Mono-material PE or PP where the shelf life allows, which recycles as a soft plastic. A foil laminate does not.
- Artwork
- Vector PDF or AI, 3 mm bleed, 4 mm safe area, fonts outlined. We check every file and send a proof before press.
- Dieline
- Supplied free with the quote, before you commit. Yours whether or not you order.
- Sample
- A plain unprinted sample at the finished size on request, for fit and construction.
- Reorders
- Skip the tooling and go straight to press at a lower unit price.
- Lead time
- Quoted with the price against your fill date rather than promised before we have seen the spec.
- Markets
- United States, United Kingdom, Canada, Australia — priced in the delivery currency, freight included.
Boards and films we build mylar seed bags on
A flexible pack is a stack of films laminated together, and the middle layer is the barrier. The structure is chosen from the shelf life you need and what you want to be able to say about recycling.
PET / PE
A printable outer and a sealing inner. Moisture barrier, modest oxygen barrier. The everyday laminate for dry goods sold quickly.
2-ply, 70–110 micronPET / AL / PE
Aluminum foil in the middle: the strongest barrier against light, oxygen and moisture. Coffee, supplements, anything with a long shelf life.
3-ply, 90–130 micronMetalized PET
A vapor-deposited metal layer. Bright, lighter and cheaper than foil, with a weaker barrier. Most silver and gold bags are this.
2–3 plyMono-material PE
Every layer polyethylene, so the bag recycles as a soft plastic. Less barrier and a slightly softer hand; the sustainable choice where shelf life allows.
100–130 micronMono-material PP
Stiffer and clearer than PE, with better heat resistance. Suits a stand-up pouch that has to hold its shape on a shelf.
90–120 micronKraft-paper laminate
A paper outer over a film barrier. The natural look with a real barrier behind it; the paper takes only a matte, flat print.
Paper 60–80gsm + filmCompostable film
PLA and cellulose structures certified for industrial compost. Lower barrier, higher cost, and no home-compost claim unless the certificate says so.
60–90 micronLDPE mailer film
Co-extruded opaque film for shipping bags: tear- and puncture-resistant, weatherproof, and recyclable where soft plastics are collected.
60–80 micronNot sure which? Say what goes in it and where it is sold — the material follows from that. Our notes on recycled, recyclable and compostable cover which claims each stock can honestly carry.
- 01
Send what you have
A dimension, a photograph beside a ruler, or the product itself. No technical drawing needed — that part is ours.
- 02
We quote and draw
A price, a dieline and a date come back together. If a different build would suit the product better, that is in the reply too.
- 03
Approve the dieline
The flat drawing is yours to check: which panel is the front, where the folds fall, how deep the cavity really is.
- 04
Artwork on the dieline
You place your design on the flat we sent, or we place it for you, and you see a proof before anything goes to press.
- 05
A sample if you want one
A plain unprinted sample at the finished size shows fit and construction — the things a drawing cannot.
- 06
Cut, printed, shipped
The die is cut once and kept, so every reorder skips the tooling and goes straight to press at a lower unit price.
Format
Vector PDF or AI where possible. Raster artwork at 300dpi at final size, in CMYK.
Bleed
3 mm past every trim line, so a fraction of drift on the cutter never leaves a white edge.
Safe area
Keep type and anything important 4 mm inside the cut and away from every fold.
Color
Convert to CMYK before sending. Uncoated stock prints lighter; a spot color is the only exact match.
Fonts
Outline them or supply the files. A missing font substitutes silently and the proof will not match.
Barcodes
On a light, matte, unvarnished patch with the quiet zone clear — a code on gloss fails the scanner.
Not set up that way? Send it anyway — fixing a file is a short conversation, and we check every one before press. Our guide to preparing print files covers each point.
Film is finished in the lacquer and the ink, not with a laminate.
Matte lacquer
A soft, non-reflective face. Hides handling marks and the most-used finish on a premium pouch.
Gloss lacquer
Wet-looking color. Reads cheaper on some categories and exactly right on confectionery.
Spot matte on gloss
A matte shape on a gloss field, or the reverse. The film equivalent of spot UV.
Metalized effects
Print over the metal layer so a color picks up the shimmer, or lay white under it for a normal color.
Registered emboss
A raised texture pressed into the film. Rare, expensive, and unmistakable in the hand.
Kraft-paper face
A paper outer laminated to the barrier. Matte and flat by nature; no varnish needed.
Not sure which suits the shelf it sells from? Say where the product is sold and we suggest one — our notes on specialty finishes show them on real boxes.
Sizing a pouch by what goes in it, not by a bag size: mylar seed bags
Film packs are specified by fill, not by dimensions. Two products of the same weight can need very different bags, because density decides volume — whole coffee beans take far more room than the same weight of powder.
- Fill weight and density
- Give us both, or send the product. We size from the volume it actually occupies, settled.
- Lay-flat width
- Half the circumference of the finished bag. It is the number a converter works to, and we calculate it from your product.
- Headspace
- Enough film above the fill to seal cleanly and for the bag to stand. Too little and the seal traps product; too much and the pack looks underfilled.
- Gusset
- Bottom gusset depth sets how the bag stands; side gussets add volume without width. Both are chosen from the shelf, not the fill.
- Seal width
- 5–8 mm. Wider on liquids and creams, which contaminate a seal, and on anything that will be posted.
- Sample fill
- A plain bag at the finished size, filled from your line, is the only reliable check before print.
Not sure your numbers are right? Send the product dimensions rather than the box dimensions and we work the box out — the full method is in our guide to measuring for a box.
Interactive · five steps · no sign-up
Spec your Mylar Seed Bags
Pick a shape, type a size, choose a film and a finish. The preview on the left redraws as you go, and the spec lands with us exactly as you set it.
Frequently asked questions
Got a question about mylar seed bags? The answers below cover what we get asked most. If yours is not here, send it with a brief, message us on WhatsApp, or call +1 503-461-4788 — we reply the same working day.
Why put seed in a mylar bag instead of a paper packet?
Paper lets water vapor through and seed absorbs it, which shortens its life. A mylar seed bag holds the seed at the moisture it was packed at.
Do mylar seed bags need to be opaque?
For most vegetable seed, no. A clear window is fine for large seed such as beans and corn. Some flower seed is light sensitive, and a full foil bag suits it better.
How small can a mylar seed bag be?
Down to a standard packet, around 3 by 4.5 inches, holding a gram or two of fine seed.
Can a mylar seed bag be resealed by the gardener?
Yes. The zipper formats close again after the first sowing, which is the point of them for seed sold in more than one dose.
What goes on the back of a printed seed bag?
Sowing depth, spacing, days to germination, sun, a sow-by date and a lot number box. We lay the back out with that information in mind.
How do I seal a mylar seed bag after filling?
With a hand impulse sealer on the open top. Keep the seal band free of seed dust, which is the usual cause of a weak seal.
Can I get mylar seed bags for microgreen seed by the pound?
Yes. Those are stand-up pouches with a bottom gusset, a wide zipper and widened side seals for the weight.
Will the lot number be printed on the mylar seed bag?
Lot numbers change too often to print. We leave a blank box for a stamp or a small label.
Are mylar seed bags food safe?
The laminate is a dry-food film, so it suits edible seed, sprouting seed and seed sold as food.
Can mylar seed bags come on a roll for a filling machine?
Yes. The same printed laminate can be supplied as rollstock for form-fill-seal equipment.
How many mylar seed bags can I order?
From 100 per size and design, which lets a small seed company print each variety separately.
Same range
