# Print areas and print sizes: measure your products and set each side

How to measure the print area of your own blanks, where to find the common sizes for each product, how centimetres, DPI and pixels relate, and how to set a print area and print size per side so every print file comes out the right size.

**A print area is the part of a product that can be printed, and its print size is how big that area is on the real product. Measure it on the smallest size you sell, leave a margin from seams, pockets and handles, and use the smaller of that and your press's largest print.**

Together, the print area and the print size decide where a customer can place a design and how many pixels the print file needs. Get them right once per product and every order arrives at the size your press expects.

## Common print sizes

There is no single standard. Each printer, blank and press has its own limits, and print-on-demand companies publish their own. Each product has a guide of its own with the sizes printers publish for every placement, in inches, centimetres and pixels at 300 DPI:

- **T-shirts:** [what size a t-shirt design should be](/guides/t-shirt-design-size/): full front, oversized, left chest, pocket, back, yoke, sleeves, youth and women's.
- **Hoodies and sweatshirts:** [hoodie and sweatshirt design sizes](/guides/hoodie-design-size/): the front above the pocket, crewneck fronts, zip hoodies, backs and sleeves.
- **Mugs:** [mug design size](/guides/mug-design-size/): the 11 oz and 15 oz wraps, the gap at the handle and two-sided prints.
- **Tote bags:** [tote bag print size](/guides/tote-bag-design-size/): standard, upright and all-over prints.
- **Caps and hats:** [hat logo size](/guides/hat-logo-size/): cap fronts, sides and backs, beanies and bucket hats, for embroidery and print.

PrintBlob's own starting sizes, with the pixels each makes at 300 DPI:

| Side | Print size (cm) | Pixels at 300 DPI |
|---|---|---|
| T-shirt front (PrintBlob's default) | 28 × 36 | 3307 × 4252 |
| T-shirt back (PrintBlob Pro's default) | 28 × 39 | 3307 × 4606 |
| Sleeve (PrintBlob Pro's starting size) | 9 × 9 | 1063 × 1063 |

A few patterns hold across most products:

- **Adult t-shirt fronts** are usually somewhere around 25 to 30 cm wide. The width is limited by the narrowest shirt you sell, the height by the collar and where the print still looks centred on the chest.
- **Backs** are often a little taller than fronts, since nothing interrupts the back below the collar.
- **Hoodie fronts** are shorter than t-shirt fronts: the print sits between the drawstrings and the pocket.
- **Women's and children's sizes** have smaller areas.
- **Mugs** are wide and short, and the handle takes part of the wrap.

## How to measure your own blanks

The print size should come from the products you actually sell, not from a table.

1. **Take the smallest size you sell** of each product. A print area that fits an XS fits everything bigger; one sized for an XL will run into the seams of a small.
2. **Lay it flat and smooth** and measure the flat, printable part: from just below the collar or drawstrings, across between the side seams, down to where the print still looks like a chest print rather than a belly print.
3. **Leave a margin.** A centimetre or two from seams, pockets and handles keeps the platen and the press clear of them.
4. **Check your press.** The print can't be bigger than your DTG platen, your DTF film width or your heat press. Use the smaller of the product's limit and the machine's.
5. **Round to a clean number** and use the same size for every size of that product. One size per side keeps the print files and the prices simple.

If you print in fixed positions, such as a chest logo and a full back, those are separate products or separate sides, each with its own size.

## Centimetres, DPI and pixels

Printers ask for files at 300 DPI (dots per inch) at the real print size. The pixels follow from the size:

**pixels = centimetres ÷ 2.54 × 300**

So a 28 cm wide print needs 28 ÷ 2.54 × 300 ≈ 3307 pixels across, and a 36 cm tall one about 4252 pixels down. That is PrintBlob's default front area: 28 × 36 cm, 3307 × 4252 pixels.

The same arithmetic, turned round, tells you how sharp a customer's image will print at the size they place it:

**effective DPI = image width in pixels ÷ (printed width in cm ÷ 2.54)**

A 2000-pixel-wide photo placed 28 cm wide prints at about 181 DPI. Placed 15 cm wide, it prints at about 339 DPI. Below about 150 DPI, softness starts to show at a normal viewing distance. The [image print size calculator](/tools/print-size/) does this sum for any image, and [print-ready t-shirt files](/guides/print-ready-t-shirt-files/) has more on DPI, transparency and file formats.

## Setting the print area and size in PrintBlob

In [PrintBlob](/), each product's mockup holds a photo per side, the print area drawn on that photo, and the print size in centimetres. With [PrintBlob Pro](/docs/pro/), open **PrintBlob › Mockups** and edit the mockup (see [Mockups](/docs/mockups/)):

1. For each side, tick **Customers can print on this side** and select **Choose photo**.
2. Drag the blue box over the printable part of the product on the photo, and resize it from its corner.
3. Enter **Print width (cm)** and **Print height (cm)**, the size you measured. Half centimetres are allowed.
4. Select **Update**.

![The Printable sides box: a t-shirt photo for Front and Back, each with a dashed print area, Choose photo, Print width (cm) and Print height (cm).](/generated/media/admin-mockup-editor-1200.webp "PrintBlob › Mockups in PrintBlob Pro: the print area on each photo and its size in centimetres.")

Two things to get right:

- **Draw the box in the same proportions as the print size.** The print file is made from the box at the print size you enter. For a 28 × 36 cm area, the box should be a little taller than it is wide, in the ratio 28 to 36. A box drawn wider or taller than that stretches the print to fit.
- **Draw it where the print really goes** on the photo, from a photo where the product is the same shape and size on every side. Customers place their design by what they see, so a box drawn too low on the photo means prints that land higher than they expected.

The designer shows the print area to customers as a dashed line, with its size underneath ("Print area 28 × 36 cm. Anything outside the dashed line is not printed.").

When a customer adds a design to the cart, PrintBlob Pro renders each printed side as a transparent PNG at exactly that print size at 300 DPI, and as a vector PDF and an SVG whose page is that size, so a 28 × 36 cm side becomes a 3307 × 4252 pixel PNG and a 280 × 360 mm page. Changing a mockup's print size affects new designs only; orders already placed keep the files they were made with.

## The 150 DPI warning

While a customer resizes an image, the designer works out its effective DPI at the size it is placed on the real product, using the print size you entered. At 150 DPI or more it says so, for example "Prints sharp: 340 DPI at this size." Below 150 DPI it warns, for example: "This image is 120 DPI at this size, so it may print blurry. Make it smaller or upload a larger file."

![The designer with an image selected on the front of a t-shirt and the note "Prints sharp: 340 DPI at this size." above the colour choices.](/generated/media/designer-dpi-1400.webp "The designer's DPI note for the selected image.")

The warning depends on the print size being right. If the mockup says 28 cm and the real print is 35 cm, every image prints softer than the designer predicted. That is one more reason to measure the real product.

## Questions shop owners ask

### What is a print area?

The part of a product that can be printed. Its print size is how big that area is on the real product, in centimetres or inches, and together they decide where a customer can place a design and how many pixels the print file needs.

### How do I measure the print area of a t-shirt?

Take the smallest size you sell, lay it flat and measure the flat, printable part from just below the collar, across between the side seams, leaving a centimetre or two from the seams. Use the smaller of that and your press’s largest print, rounded to a clean number.

### How many pixels does a print area need?

Its size in centimetres divided by 2.54 and multiplied by 300: a 28 × 36 cm print area needs 3307 × 4252 pixels at 300 DPI.

### Why must the print area box have the print size’s proportions?

The print file is made from the box at the print size you enter, so a box drawn wider or taller than the print size’s proportions stretches the print to fit.

### What happens if the print size I enter is wrong?

The print files come out at the wrong size, and the designer’s sharpness warning is wrong too: if the mockup says 28 cm and the real print is 35 cm, every image prints softer than the designer predicted.

## Next steps

- Set up each product's sides: [Mockups](/docs/mockups/) in the PrintBlob docs.
- Add more products: [sell custom hoodies, mugs, tote bags and caps](/guides/custom-hoodies-mugs-tote-bags-caps-woocommerce/).
- [Try the designer](/#demo): upload a photo, resize it, and watch the DPI note change.

## Get PrintBlob Pro

Pro adds print-ready files, back printing, a 3D view and a production print queue to the free designer. Paid with Stripe in US dollars, no tax added; one domain per licence.

- **$69 a year**: [Buy the yearly licence](https://printblob.com/pricing/#buy). Full refund within 14 days.
- Limited-time offer until 31 December 2026: **$99 once**: [Buy the lifetime licence](https://printblob.com/pricing/#buy). Full refund within 14 days.

## More guides

- [How to make a custom t-shirt website with WooCommerce](https://printblob.com/guides/sell-custom-t-shirts-woocommerce/)
- [Print-ready t-shirt files: format, transparency and resolution](https://printblob.com/guides/print-ready-t-shirt-files/)
- [What size should a t-shirt design be? Sizes by placement in inches, centimetres and pixels](https://printblob.com/guides/t-shirt-design-size/)
- [Photographing t-shirts for a product designer](https://printblob.com/guides/t-shirt-photos-for-a-product-designer/)
- [WooCommerce product designer plugins compared](https://printblob.com/guides/woocommerce-product-designer-plugins-compared/)
- [Let customers upload a logo or photo to a WooCommerce product](https://printblob.com/guides/customer-image-upload-woocommerce/)
- [Add custom text to WooCommerce products: names, slogans and messages](https://printblob.com/guides/custom-text-woocommerce-products/)
- [How to price custom t-shirt printing](https://printblob.com/guides/price-custom-t-shirt-printing/)
- [Sell custom hoodies, mugs, tote bags and caps in WooCommerce](https://printblob.com/guides/custom-hoodies-mugs-tote-bags-caps-woocommerce/)
- [DTF vs DTG vs screen printing for a small print shop](https://printblob.com/guides/dtf-vs-dtg-vs-screen-printing/)
- [What size should a logo be on a hat? Cap, beanie and bucket hat sizes for embroidery and print](https://printblob.com/guides/hat-logo-size/)
- [What size should a hoodie design be? Hoodie and sweatshirt print sizes in inches, centimetres and pixels](https://printblob.com/guides/hoodie-design-size/)
- [Mug design size: 11 oz and 15 oz sublimation template sizes in inches, centimetres and pixels](https://printblob.com/guides/mug-design-size/)
- [Tote bag print size: design sizes in inches, centimetres and pixels](https://printblob.com/guides/tote-bag-design-size/)
- [Team and group orders with names and numbers in WooCommerce](https://printblob.com/guides/team-orders-names-numbers-woocommerce/)
- [A checklist for running a WooCommerce print-on-demand shop](https://printblob.com/guides/woocommerce-print-on-demand-checklist/)
- [How PrintBlob Pro makes a 3D product from your photos](https://printblob.com/guides/3d-product-from-photos/)
- [Artwork approval for custom prints: a live mockup or emailed proofs](https://printblob.com/guides/artwork-approval-live-preview-vs-email-proofs/)
- [DTF print file requirements: PNG, 300 DPI and a transparent background](https://printblob.com/guides/dtf-print-file-requirements/)
- [Set up an Instagram shop with WooCommerce for custom prints](https://printblob.com/guides/woocommerce-instagram-shop-custom-prints/)
- [WooCommerce local pickup for print shops: set-up and common problems](https://printblob.com/guides/woocommerce-local-pickup-print-shop/)
- [WooCommerce order statuses for a print shop: custom statuses for artwork, printing and pickup](https://printblob.com/guides/woocommerce-order-status-print-shop/)
- [How to add a size chart in WooCommerce for t-shirts and hoodies](https://printblob.com/guides/woocommerce-size-chart-t-shirts/)
- [WooCommerce personalised product plugins: product add-ons or a product designer](https://printblob.com/guides/woocommerce-personalised-product-plugin/)
- [WooCommerce colour swatches for t-shirts: swatch plugins, variation photos or one recoloured photo](https://printblob.com/guides/woocommerce-colour-swatches-t-shirts/)
- [DTF gang sheet builder for WooCommerce: sell gang sheets and transfers on your own website](https://printblob.com/guides/dtf-gang-sheet-builder-woocommerce/)
- [What you need to start a t-shirt printing business: equipment, supplies and an online shop](https://printblob.com/guides/start-t-shirt-printing-business/)
- [Jersey name and number size: back, front and sleeve numbers by sport in inches, cm and pixels](https://printblob.com/guides/jersey-name-and-number-size/)
- [What size should a sublimation design be for shirts? Paper sizes, design sizes and the file format](https://printblob.com/guides/sublimation-shirt-design-size/)

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Page: https://printblob.com/guides/print-area-sizes-by-product/

See also: [docs](https://printblob.com/docs/index.md), [features](https://printblob.com/features/index.md), [situations](https://printblob.com/situations/index.md), [compare](https://printblob.com/compare/index.md), [demos](https://printblob.com/demos/index.md), [tools](https://printblob.com/tools/index.md), [themes](https://printblob.com/themes/index.md).