Wedding Invitation Paper Weights and GSM Explained

GSM stands for grams per square metre. It measures how heavy and thick a paper or card is. The higher the GSM, the sturdier the sheet. For wedding invitations, you usually want something that feels substantial but still fits through a standard letterbox.

A good range for the main invitation card is 250 to 350 GSM. This feels premium without being too rigid. For outer envelopes, use a lighter paper around 100 to 120 GSM. For inner envelopes, if you use them, 90 to 120 GSM is fine. For reply cards and information slips, 200 to 250 GSM works well.

If you are printing at home, stay under 300 GSM for most home printers. Very thick card can jam or curl. Test one sheet first.

There is no single best GSM, because it depends on your printer and your style. For a classic, premium feel, 300 GSM is a popular choice. It is thick enough to feel special but still works with many home printers. If you want a softer, more traditional feel, 250 GSM is elegant and easier to fold.

For a modern, heavyweight look, 350 GSM feels like a luxury card, but it is harder to fold and may need a heavier envelope. For handmade or layered invitations, you can mix weights: a 300 GSM main card with a 200 GSM belly band or backing.

If you are posting invitations, remember that heavier card costs more in postage. Keep the total weight under the first-class letter limit if you can, or be ready to add extra stamps.

The most common wedding invitation size in the UK is A6, which is 105 mm by 148 mm. It fits a C6 envelope and is easy to post. A5, which is 148 mm by 210 mm, is also popular for a larger, more dramatic invitation. A5 invitations usually need a C5 envelope.

If you want a square invitation, a common size is 140 mm by 140 mm. Square envelopes cost more to post because they are not standard letter size. The Post Office may charge a larger letter rate. Check with your local post office before you buy.

For a standard rectangular invitation, A6 or A5 are the easiest and cheapest to post. You can also have a folded A5 card that opens like a booklet, which gives you more space for details.

Printing at home can look great if you choose the right paper and settings. Use a good quality card, at least 250 GSM, and set your printer to the correct paper type, such as cardstock or heavy weight. Print a test page on plain paper first to check alignment and colours.

Use a high resolution, at least 300 dpi, for your design. If you are printing text, make sure it is sharp and not pixelated. Avoid printing on both sides of heavy card if your printer is not designed for it, as it can cause smudging.

Let the ink dry fully before you touch it. Some home printers use ink that smears, so check the manufacturer's guidance. You can also use a laser printer, which gives a dry, smudge-free finish. If your printer struggles with thick card, use a lighter card for the main sheet and add a separate backing layer for weight.

Foil adds a shiny metallic finish to text or designs. There are a few ways to do it. Professional printing uses a heated metal plate to press foil onto the card. This gives a crisp, premium result but costs more. You can also use a cutting machine, such as a popular electronic cutter, with a foil tool and foil sheets.

For home foiling, you need a laminator or a foiling pen. A foiling pen writes with a special adhesive, then you apply foil and heat it with a laminator. This works well for small text and simple designs. For larger areas, a cutting machine with a foiling attachment is easier and more consistent.

If you want a professional finish without the fuss, order foil-pressed invitations from a print shop. Foil comes in gold, silver, rose gold and many colours. It looks elegant and feels luxurious, but it is usually more expensive than plain printing. Keep your foil design simple, because too much foil can look busy.

The number of stamps depends on the weight and size of your invitation. A standard A6 invitation with a single card and envelope usually weighs under 100 grams and needs one first-class or second-class stamp. If you add extra cards, a heavy card, or a square envelope, it may weigh more and need two stamps.

Square envelopes larger than 240 mm by 165 mm are classed as large letters and need more postage. To be safe, weigh your completed invitation at the post office or on a kitchen scale. You can also use the Post Office price finder online, but the rules can change, so check before you post.

If you are sending many invitations, buy stamps in bulk. You can also ask the post office to check the weight for you. Always add the stamps before you seal the envelope, so you can adjust if needed.

The cost of printing invitations varies a lot. It depends on the quantity, paper weight, finish, and whether you use a professional printer or print at home. Professional printing costs more but gives a consistent, high-quality result. Home printing costs less per sheet, but you need to buy ink and good card.

Foil, letterpress, and embossing are more expensive finishes. Digital printing is usually the most affordable. If you have a small budget, you can design your own and print at home on quality card. If you want a premium feel, consider a mix: a simple digital print on heavy card with a foil-lined envelope.

Always ask for samples before you order. That way you can feel the paper and see the colours. Many UK print shops offer sample packs. Compare a few quotes, but remember that the cheapest option may not give the best result. Your invitations set the tone for your wedding, so it is worth investing in good paper.