Note: At the time of its release in December 2020, Cass was offered for free. Today you may buy the Cass T-Shirt and Book of Hacks as a pattern-and-e-book combo. The pattern is no longer complimentary. Please disregard mentions of the pattern being free. Thanks for understanding.

Cass is a T-shirt pattern.

Say howdy to Cass, a T-shirt pattern with beyond-basic style! This easy-to-sew wardrobe staple is destined for tried-and-true status in your sewing practice.

Speed is the name of the game when it comes to Cass. Because this T-shirt pattern compromises only three pattern pieces (front, back, and neckband), the time from printing the PDF to cutting your fabric to the final backstitch will be minimal. Hooray for (almost) instant gratification!

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Cass T-Shirt Pattern Description

Cass is a comfy — but not dumpy! — T-shirt with grown-on (i.e., not set-in) sleeves. Its fit is relaxed and boxy, with the curved hem hitting the full hip.

This T-shirt pattern features a slightly scooped crewneck and rounded bottom hem. Cass’ long-ish cap sleeves cover your shoulders and upper arms to protect against sunburn (you are welcome, fellow pale humans!).

Speaking of shoulders, the shoulder seams sit on the front the T-shirt, creating visual interest even on a solid-colored top. Front-to-back asymmetry FTW!

The Cass T-shirt pattern features a rounded hem.

Size Ranges for Cass

The T-shirt pattern comes in two size ranges to fashionably clothe human bodies of myriad volumes! The “B” range is for bust sizes with a difference of 2 inches (5.1 cm) between the upper bust and full bust. The “D” range is for bust sizes with a difference of 4 inches (10.2 cm) between the upper bust and full bust.

The B range accommodates full busts from 31.4 inches (79.9 cm) to 45 inches (114.3 cm) and full hips from 34.3 inches (87.2 cm) to 47.8 inches (121.3 cm).

The D range accommodates full busts from 42.3 inches (107.3 cm) to 66 inches (167.6 cm) and full hips from 46.3 inches (117.5 cm) to 70 inches (177.8 cm).

As an added bonus, Cass has a lot of design ease in the bust, waist, and hips. There’s a lot of grace here if you’re not hot to do a bust adjustment.

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Fabric Recommendations

This T-shirt pattern is designed for super-duper drapey and lightweight knits, such as the poly-spandex ITY knit featured in the photos. Cass is meant to be airy and fluid, flowing over your body.

We also recommend knits of rayon and bamboo. I would love to make a Cass T in a featherweight linen knit. I also think Cass would be fierce in a metallic lamé with raw edges!

Just to be sassy, I sewed Cass in a cotton-poly knit: Striped Cass T-Shirt and New Ginger Jeans.

Sie Macht Cass T-shirt pattern. This knit top features grown-on sleeves.
Sie Macht Cass front technical drawing.
Sie Macht Cass back technical drawing.
Sie Macht Cass D size range. The T-shirt pattern comes in misses and plus size ranges.

Sew Your Cass, Your Way

For your information, the pictured royal blue Cass T-shirt is size 6/8B (B as in B size range), with 1 inch added to the length to accommodate a long waist. The pictured light blue Cass is size 26/28D with no modifications.

Beyond fit mods, an easy way to customize YOUR Cass is color blocking. Cut the front pattern piece in one color and the back and neckband pieces in another.

Personally, I’m itching to run the front stripes of a future Cass horizontally… and the back stripes vertically! Another eye-catching idea could help you bust your fabric stash. Use small yardages of different fabrics for the front and back.

How will you customize your Cass? I can’t wait to see what you come up with. Don’t forget to tag @sie.macht.sewing and use hashtag #smcass to show off your creations and to inspire other sewists!

P.S. To help you sew your best Cass (or any T-shirt, really), check out these blog posts:

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