Designing in Adobe Illustrator for DTF Printing: How to Get Colours That Print Exactly As You Expect

You spend hours perfecting your design in Adobe Illustrator. The purple is exactly right, the brand colours pop, everything looks stunning on screen. Then the transfers arrive — and that rich purple has turned blue.

Nothing went wrong with the print. The problem happened months earlier, the moment the colour was picked. In this guide we'll show you how to set up Illustrator so that what you see on screen is what comes off our printers — every single time.

If you haven't already, read our overview of why screen and print colours differ first. This post gets practical, specifically for Illustrator users.

Why your screen shows colours that can't be printed

Your monitor creates colour with glowing red, green and blue light (RGB). Printers — including our industrial DTF machines — create colour by layering cyan, magenta, yellow and black inks (CMYK). Light can produce colours that ink physically cannot. That mismatch is called the gamut: the range of colours a device can reproduce.

Most colours convert between the two just fine. But the most vivid ones — electric purples and violets, neon greens, ultra-bright oranges and blues — exist only in light. When a file containing them goes to print, the software substitutes the nearest printable colour, and the result can shift noticeably. Vivid violet is the classic casualty: a colour like #520CC7 converts to roughly equal parts cyan and magenta, and prints blue.

Step 1: Set your document to CMYK before you start

When you create a new document in Illustrator, check the colour mode:

File → New → Advanced Options → Color Mode → CMYK

For an existing file: File → Document Color Mode → CMYK Color.

With the document in CMYK, Illustrator's colour tools work within the printable range from the start — you simply can't pick a colour that won't print. This one setting prevents most colour surprises on its own.

Step 2: Learn to spot the gamut warning

If you work from a hex code or in RGB, watch the Color Picker. When you select a colour that can't be printed, Illustrator shows a small warning triangle (⚠) next to the colour swatch — the "out of gamut" warning.

That triangle means: this colour will not print the way it looks on your screen.

The fix is one click: click the small swatch directly beneath the triangle and Illustrator snaps your colour to the nearest printable equivalent. What you see then is an honest preview of what our printers will produce. If you're happy with it, you're safe to proceed. If it looks too dull, adjust the CMYK values until you find a vivid colour that stays inside the gamut.

Step 3: Preview your print with Proof Colors

Illustrator can simulate printed output on screen:

View → Proof Setup → Working CMYK, then View → Proof Colors.

Toggle Proof Colors on and off while you design. If a colour changes dramatically when it's on, it will change just as dramatically in print. No surprises.

Step 4: Set brand colours directly in CMYK values

For logos and brand work, don't rely on hex codes — they're screen values. Define your colours in CMYK numbers, so the recipe going to the printer is exactly the one you chose. Some reliable starting points:

These are starting points, not gospel — the definitive answer is a printed swatch (more on that below).

Step 5: Export correctly for the gang sheet builder

Our gang sheet builder takes PNG files, and a few export settings make all the difference:

1. File → Export → Export As → PNG
2. Resolution: 300 ppi (never 72 — that's the web default and prints blurry)
3. Background: Transparent
4. Anti-aliasing: Art Optimized

Size your artboard to the actual print size before exporting, with the design running edge-to-edge — the builder measures your image by its full canvas, so empty space around the design throws off the sizing.

The only 100% reliable check: a printed swatch

Even a perfectly calibrated screen is still a screen. For brand colours that have to be exact, order our physical CMYK Colour Swatch (£10 for DTF, £15 for UV-DTF). It's a chart of real CMYK values printed on our actual machines and film — find the shade you love on the swatch, use its CMYK values in Illustrator, and what arrives will match what you chose. It pays for itself the first time it saves you a misprinted sheet.

Quick pre-order checklist

• Document colour mode set to CMYK
• No gamut warnings on any colour in the design
• Proof Colors preview checked
• Brand colours defined as CMYK values (from a printed swatch, ideally)
• Exported as PNG, 300 ppi, transparent background, artwork edge-to-edge
• Final check in the builder's zoom preview — what you see is what we print

FAQ

Why did my purple print as blue?
Vivid purples and violets sit outside the CMYK printable range. When converted for print they lean towards blue because the converted recipe contains nearly equal cyan and magenta. Use a print-safe purple such as C70 M100 Y0 K5 instead.

The builder asks for a PNG — isn't PNG an RGB format?
Yes, PNG files are technically RGB. What matters is that the colours in the design are chosen inside the CMYK gamut. Design in CMYK mode, resolve any gamut warnings, then export to PNG — the colours will survive the conversion because they were printable to begin with.

Do you colour-correct my files before printing?
No — we print your file exactly as supplied. That's how we keep prices low and turnaround same-day. The tools above put colour control entirely in your hands.

My colours looked fine in Canva/Photoshop — does this apply there too?
The same physics applies to every design tool. Photoshop has the same gamut warning and proofing tools as Illustrator; Canva works only in RGB, so a printed swatch is even more important for Canva users.

Ready to put it into practice? Build your gang sheet — order by 1pm and it ships the same day. Questions about a specific colour? Raise a ticket and we'll help before you order.