How to Design a Custom T-Shirt: File Types, Placement & Size Guide
Quick Answer
Use a transparent PNG at 300 DPI or a vector file (SVG, AI, EPS, PDF). For a full-front design, size it 10 to 12 inches wide and place it 3 to 4 inches below the collar. For a left-chest logo, use 3 to 4 inches wide, centered 3 inches below the neckline and 2 to 3 inches from the center toward the armpit. Set color mode to sRGB for DTF printing.
File Types: What Your Printer Actually Needs
File format is the first and most common source of print errors. Most problems- white boxes around designs, blurry edges, color shifts- come from submitting the wrong file type rather than a design problem.
- .PNG: Supports transparent backgrounds. Use for photographic or multi-color artwork. Must be at 300 DPI at the actual print size, not screen resolution (72 DPI).
- .SVG /.AI /.EPS: Vector files scale to any print size without losing quality. Ideal for logos, text, and flat-color graphics. Resolution does not apply to vector files
- .PDF: Accepted when exported from a vector program (Illustrator, Affinity Designer). Confirm the artwork is vector-based inside the PDF, not a rasterized image.
- .JPEG /.JPG: JPEG does not support transparent backgrounds. It will print a white rectangle around the artwork. Also uses lossy compression that degrades print quality.
- .PSD: Accepted by some printers but not all. Export a flattened transparent PNG from Photoshop instead. Confirm with your printer before submitting a layered PSD.
- .GIF /.WEBP: Web-only formats. Not suitable for print. GIF is limited to 256 colors; WEBP is not supported by print software.
For DTF printing specifically, a transparent PNG is the preferred format. DTF transfers print on film and then heat-press onto fabric, so the transparent areas of your file become the edges of the transfer. A white background in your file prints as white on the shirt.
The blank you print on matters as much as the file format. For guidance on fabric, weight, and construction, see Best Premium Custom T-Shirts: A Complete Buyer's Guide.
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Resolution: DPI and Pixel Dimensions
300 DPI (dots per inch) is the standard for custom t-shirt printing. DPI only applies to raster files (PNG, JPEG, PSD); vector files do not have a DPI setting.
The mistake most people make is checking the pixel count without checking the DPI. A 1000 x 1000 pixel image at 72 DPI prints at about 14 inches and looks blurry. The same pixel count at 300 DPI prints at just over 3 inches and looks sharp. Always set both the canvas size in inches and the resolution in DPI at the same time, before you start designing.
300 DPI Reference: Inches to Pixels
- 3 inches: (left chest logo, min)
- 4 inches: (left chest logo, standard
- 4 inches: (sleeve)
- 8 inches: (center chest, min)
- 10 inches: (full front, min)
- 12 inches: (full front, standard)
- 14 inches: (full front, oversized)
Color Mode: sRGB vs CMYK
Color mode determines how your printer reads color information. Using the wrong mode does not always cause obvious errors, but it can shift colors between what you see on screen and what prints on the shirt.
| Print Method | Correct Color Mode | Why |
|---|---|---|
| DTF (Direct-to-Film) | sRGB | DTF printers use digital inkjet technology to print from RGB color data. Submitting a CMYK file forces a conversion that can dull saturated colors. |
| Screen Printing | CMYK | Screen printing mixes inks physically (cyan, magenta, yellow, key/black). CMYK separations map directly to individual screens. |
| Direct-to-Garment (DTG) | sRGB | DTG uses the same inkjet process as DTF and natively interprets sRGB. |
Custom Apparel US uses DTF printing. Submit your files in sRGB. If you designed in CMYK, export or convert to sRGB before sending; most design tools (Illustrator, Photoshop, Canva) include this option in the export settings.
T-Shirt Design Placement Guide
Placement is measured from fixed reference points: the collar (neckline seam), the center front seam, and the armpit seam. Every location below uses these references.
Location 01/Full Front
- Width 10" to 12"
- Oversized
- From collar 3" to 4" down
- Alignment Centered
Location 02/Center Chest
- Width 8" to 10"
- From collar 3" to 5" down
- Alignment Centered
- Use case: logos, text
Location 03/Left Chest (Logo)
- Width 3" to 4"
- Range 2.5" min / 5" max
- From collar 3" down
- From center 2" to 3" left
Location 04/Full Back
- Width 10" to 12"
- From collar 3" to 4" down
- Alignment Centered
- Note Separate file
Location 05/Sleeve
- Width 3" to 4"
- Position Upper arm, centered
- Avoid Seams
- Note Separate file
Location 06/Back Yoke (Upper Back)
- Width 4" to 6"
- From collar 1" to 2" down
- Alignment Centered
- Use case Names, numbers
T-Shirt Design Size Chart
The table below combines placement location, design width, and the corresponding pixel width at 300 DPI. Use this as the reference when setting up your canvas.
| Placement | Design Width | Pixels at 300 DPI | Distance from Collar | Alignment |
|---|---|---|---|---|
| Full Front | 10" to 12" | 3000 to 3600 px | 3" to 4" down | Centered |
| Full Front (Oversized) | up to 14" | up to 4200 px | 3" to 4" down | Centered |
| Center Chest | 8" to 10" | 2400 to 3000 px | 3" to 5" down | Centered |
| Left Chest Logo | 3" to 4" (max 5") | 900 to 1200 px | 3" down | 2" to 3" from center |
| Full Back | 10" to 12" | 3000 to 3600 px | 3" to 4" down | Centered |
| Back Yoke | 4" to 6" | 1200 to 1800 px | 1" to 2" down | Centered |
| Sleeve | 3" to 4" | 900 to 1200 px | Upper arm area | Centered, avoid seams |
Scaling Designs Across Shirt Sizes
A 12-inch-wide design that fits an adult XL chest looks oversized on a youth small and undersized on a 3XL. The proportions need to scale with the garment. Use the guidelines below as starting points; the goal is for the design to occupy roughly the same visual proportion of the chest across all sizes.
| Shirt Size Category | Full Front Width | Left Chest Logo |
|---|---|---|
| Youth / Kids (XS to L) | 7" to 9" | 2" to 3" |
| Women's Fitted (XS to XL) | 7.5" to 9.5" | 2.5" to 3.5" |
| Unisex Adult (S to XL) | 10" to 12" | 3" to 4" |
| Unisex Adult (2XL to 3XL) | 12" to 14" | 4" to 5" |
If you are ordering a mixed-size run, design for the mid-range adult size (S to XL) as your base. Most printers scale the artwork proportionally when printing across multiple garment sizes, but confirm this with your printer before ordering a large batch.
Three Rules That Prevent the Most Common Errors
The Three-Finger Rule
Hold three fingers horizontally below the collar seam. That gap, roughly 3 inches, is where the top edge of a standard front graphic should sit. It keeps the design centered on the visible chest rather than crowding the neckline or drifting toward the belly.
Stay Away from Seams
DTF transfers and screen prints stretch and distort when they cross a seam. On sleeves, stop the design at least half an inch from the shoulder seam and the cuff hem. On side-seam shirts, do not extend a back design to the edges of the shirt — keep a half-inch margin from the side seams.
Send One File Per Print Location
The front, back, left chest, and sleeve are all separate print jobs that require separate setups. Combine them into one file only if your printer explicitly requests a composite layout. Most DTF printers in Richardson and the Dallas area, including Custom Apparel US, prefer individual files labeled by location (front.png, back.png, leftchest.png).
Left Chest Logo Placement: The Full Breakdown
Left-chest placement is the most common location for corporate and branded shirts, and it has the tightest measurement tolerance of any location. Getting it wrong by even half an inch results in a logo that looks off-center or too close to the armpit.
The correct reference point is the intersection of 3 inches below the neckline seam and 2 to 3 inches from the center-front seam toward the left armpit. Place the center of your logo at this intersection. For a 4-inch logo, the left edge of the artwork will sit roughly 4 inches from center, and the right edge roughly 2 inches from center.
Logo size and legibility: A logo narrower than 2.5 inches on a standard adult shirt loses fine detail in text and thin lines. If your logo contains text smaller than about 8 points at 4 inches wide, confirm a test print before running a full order. DTF handles fine detail well, but line weights below 0.5 pt can merge at smaller print sizes.
How to Send Your Design to Custom Apparel US
We print custom t-shirts using DTF (Direct-to-Film) at our Richardson, TX facility. Production runs 1 to 2 business days after artwork approval, with next-day on-site pickup available.
When you send your design, include:
- File format: transparent PNG at 300 DPI or a vector file (SVG, AI, EPS, PDF)
- Color mode: sRGB
- Dimensions: canvas sized to the intended print width in inches
- Print location(s): one file per location, labeled by placement
- Garment details: color, size breakdown, and quantity
We send a digital proof before any printing starts. If your file needs adjustment, resolution, background, or color conversion, we flag it before production rather than printing and billing for a bad result.