Official Shirtz Cool Merch The Idk I Don’t Know I Straight Up Know Nothing Tee Shirt

-8%
Official Shirtz Cool Merch The Idk I Don't Know I Straight Up Know Nothing Tee Shirt
(4 customer reviews)

Original price was: $24.99.Current price is: $22.99.

Estimated delivery dates: Jul 27, 2026 - Aug 4, 2026
Sizing chart
Don’t have your favorite color, size? Please contact us directly if you would like to have your own one.
checkout

Unisex Standard T-Shirt

SizeChest WidthShirt Length
S18 in28 in
M20 in29 in
L22 in30 in
XL24 in31 in
2XL26 in32 in
3XL28 in33 in
4XL30 in34 in
5XL32 in35 in
Note: Allow for a tolerance level of 1 inch

Unisex Hoodie

SizeChest WidthShirt LengthSleeve Length
S20 in27 in33.5 in
M22 in28 in34.5 in
L24 in29 in35.5 in
XL26 in30 in36.5 in
2XL28 in31 in37.5 in
3XL30 in32 in38.5 in
4XL32 in33 in39.5 in
5XL34 in34 in40.5 in
Note: Allow for a tolerance level of 1 inch

Unisex Sweatshirt

SizeChest WidthShirt LengthSleeve Length
S20 in27 in33.5 in
M22 in28 in34.5 in
L24 in29 in35.5 in
XL26 in30 in36.5 in
2XL28 in31 in37.5 in
3XL30 in32 in38.5 in
4XL32 in33 in39.5 in
5XL34 in34 in40.5 in
Note: Allow for a tolerance level of 1 inch

Men's Zip Hoodie

SizeChest WidthShirt LengthSleeve Length
S19.25 in27 in33.5 in
M21.25 in28 in34.5 in
L23.25 in29 in35.5 in
XL25.25 in30 in36.5 in
2XL27.25 in31 in37.5 in
3XL29 in32 in38.5 in
Note: Allow for a tolerance level of 1 inch

Men's Long Sleeved T-Shirt

SizeChest WidthShirt LengthSleeve Length
S18 in28 in33.5 in
M20 in29 in35 in
L22 in30 in36.5 in
XL24 in31 in38 in
2XL26 in32 in39.5 in
3XL28 in33 in39.5 in
4XL30 in34 in39 in
5XL32 in35 in40.5 in
Note: Allow for a tolerance level of 1 inch

Men's V-Neck T-Shirt

SizeChest WidthShirt Length
S18 in28 in
M20 in29 in
L22 in30 in
XL24 in31 in
2XL26 in32 in
3XL28 in33 in
Note: Allow for a tolerance level of 1 inch

Men's Tank Top

SizeChest WidthShirt Length
S18 in28 in
M20 in29 in
L22 in30 in
XL24 in31 in
2XL26 in32 in
3XL28 in33 in
Note: Allow for a tolerance level of 1 inch

Ladies Long Sleeve T Shirt

SizeChest WidthShirt Length
S18 in28 in
M20 in29 in
L22 in30 in
XL24 in31 in
2XL26 in32 in
3XL28 in33 in
Note: Allow for a tolerance level of 1 inch

Ladies T Shirt

SizeChest WidthShirt LengthSleeve Length
S17.25 in25.5 in13.25 in
M19.25 in26 in14 in
L21.25 in27 in14.75 in
XL23.25 in28 in15.75 in
2XL25.25 in28.5 in16.75 in
3XL27.25 in29 in17.5 in
Note: Allow for a tolerance level of 1 inch

Ladies Hooded Sweatshirt

SizeChest WidthShirt LengthSleeve Length
S20 in26 in32 in
M22 in27.5 in33 in
L24 in28 in34.5 in
XL26 in29.5 in35.5 in
2XL28 in30 in37 in
Note: Allow for a tolerance level of 1 inch

Ladies Tank Top

SizeChest WidthShirt Length
S15 in27.56 in
M16.1 in27.95 in
L17 in28.35 in
XL18.1 in29.13 in
2XL18.9 in29.53 in
Note: Allow for a tolerance level of 1 inch

Ladies V Neck T Shirt

SizeChest WidthShirt Length
S17.25 in25.5 in
M19.25 in26 in
L21.25 in27 in
XL23.25 in28 in
2XL25.25 in28.5 in
3XL27.25 in29 in
Note: Allow for a tolerance level of 1 inch

Youth T Shirt

SizeChest WidthShirt LengthSleeve Length
XS (4-5 years)16 in20.5 in13.5 in
S (6-7 years)17 in22 in14.5 in
M (8-9 years)18 in23.5 in15.5 in
L (10-11 years)19 in25 in16.5 in
XL (12-13 years)20 in26.5 in17.5 in
Note: Allow for a tolerance level of 1 inch

Mug

Twill Cap

360 CrownFront Crown
22.24 in12.6 in
Visor's LengthVisor's Width
6.69 in4.53 in
Note: Allow for a tolerance level of 1 inch

Tumbler

Cloth Face Mask

Baseball Jersey Shirt

SizeLengthBustShoulder
S29.92 in34.65 in14.96 in
M30.31 in37.8 in16.14 in
L30.71 in40.94 in17.32 in
XL31.1 in44.09 in18.5 in
2XL31.5 in48.03 in19.69 in
3XL31.89 in51.97 in20.87 in
4XL32.28 in55.91 in22.05 in
5XL32.68 in59.84 in23.23 in
Note: Allow for a tolerance level of 1 inch

Basketball Jersey Tank

SizeLengthBust
XS27.6 in39.2 in
S28.4 in40.8 in
M29.2 in42.4 in
L30 in45.6 in
XL30.8 in48 in
2XL31.6 in50.4 in
3XL32.4 in52.8 in
4XL33.2 in55.2 in
5XL34 in57.6 in
Note: Allow for a tolerance level of 1 inch

Basketball Suit

SizeLengthBustShoulderPant LengthsWaistHip
XS24.8 in36.22 in13.39 in18.11 in23.62 in38.58 in
S25.79 in37.8 in13.78 in18.9 in25.2 in40.16 in
M26.77 in39.37 in14.17 in19.69 in26.77 in41.73 in
L27.76 in40.94 in14.57 in20.47 in28.35 in43.31 in
XL28.74 in42.52 in14.96 in21.26 in29.92 in44.88 in
2XL29.72 in44.09 in15.35 in22.05 in31.5 in46.46 in
3XL30.71 in45.67 in15.75 in22.83 in33.07 in48.03 in
4XL31.69 in47.24 in16.14 in23.62 in34.65 in49.61 in
5XL33.07 in48.82 in16.54 in32.28 in36.22 in51.18 in
Note: Allow for a tolerance level of 1 inch

Hawaiian Shirt

SizeLengthBustSleeve
XS27.17 in37.8 in16.54 in
S27.95 in40.94 in17.32 in
M28.74 in44.09 in18.11 in
L29.53 in47.24 in19.09 in
XL30.31 in50.39 in19.88 in
2XL31.1 in53.54 in20.87 in
3XL31.89 in56.69 in21.65 in
4XL32.68 in59.84 in22.64 in
5XL34.25 in62.99 in24.02 in
Note: Allow for a tolerance level of 1 inch

Keep your casual wardrobe fun and relatable with the Official Shirtz Cool Merch The Idk I Don’t Know I Straight Up Know Nothing Tee Shirt, a playful graphic tee that combines humor with everyday comfort. Perfect for pairing with denim, cargo pants, or shorts, it works well for social gatherings, travel, daily wear, or relaxing weekends. Its versatile styling and timeless design make it an easy choice for anyone who enjoys expressive apparel with a relaxed and modern look.

T Shirt:
  • 100% Premium polyester which is ultra-soft and incredibly comfortable.
  • Fabric is durable and resistant to wrinkles, shrinking, and mildew.
  • Features ensure long-lasting color vibrancy even after machine washing.
Care Instruction:
  • Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
  • Do not use bleach
  • Do not iron
  • Do not dry clean
  • Do not tumble dry
Hoodie:
  • Material: 90% polyester, 10% spandex.
  • The soft sherpa fleece on the inside is extremely soft and cosy.
  • Flat contrasted drawstring, Front pouch kangoroo pockets. Elastic waist and cuffs.
  • Garment care: Machine washable in gentle, recommend hand wash in cold water, line dry, do not bleach, low iron if needed.
Care Instruction:
  • Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
  • Do not use bleach
  • Do not iron
  • Do not dry clean
  • Do not tumble dry
Sweatshirt:
  • 95% Polyester, 5% Spandex.
  • Dye-sublimation printing, colors will never be faded or peeled.
  • It is used to react to your body's temperature to keep you warm in the winter and cool in autumn.
Care Instruction:
  • Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
  • Do not use bleach
  • Do not iron
  • Do not dry clean
  • Do not tumble dry
Zip Up Hooded Sweatshirt:
  • Material: 10% Cotton, 90% Polyester.
  • Sherpa lining can provide better insulation and extra down-like warmth.
  • Relaxed Fit – generously sized for ease of movement.
  • This jacket is custom-designed in a classic style and is a must-have item in the wardrobe.
Care Instruction:
  • Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
  • Do not use bleach
  • Do not iron
  • Do not dry clean
  • Do not tumble dry
Long Sleeve T Shirt:
  • 100% Premium polyester which is ultra-soft and incredibly comfortable.
  • The soft and stretchy fabric gives you comfy all day long, is high quality, quick-drying, and suitable for autumn and winter.
  • Long Sleeve Shirts have been in fashion for ages and they will always be an essential wardrobe staple for gentlemen.
  • Whether you want to go out for sports or just want to put them on as leisurewear, whether you want to pair them with a trouser or shorts, they always look great and offer an easy choice for all occasions!
  • Suitable for special occasions such as Christmas, birthdays, celebrations, and housewarming gifts.
  • Print: Dye-sublimation printing.
Care Instruction:
  • Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
  • Do not use bleach
  • Do not iron
  • Do not dry clean
  • Do not tumble dry
Youth T Shirt:
  • 100% Premium polyester which is ultra-soft and incredibly comfortable.
  • Fabric is durable and resistant to wrinkles, shrinking, and mildew.
  • Features ensure long-lasting color vibrancy even after machine washing.
Care Instruction:
  • Machine wash at max. 30ºC/86ºF with short spin cycle, inside out with like colors
  • Do not use bleach
  • Do not iron
  • Do not dry clean
  • Do not tumble dry
Hawaiian Shirt: The Hawaii shirts are really the ideal choice to wear in the tropical atmosphere when the summer and the holiday are coming so soon. They are cool and more interesting as compared to typical mono-color clothes. They are casual and formal at the same time.
  • Material: 95% Polyester - 5% Spandex
  • Printing technique: dye-sublimation
Baseball Jersey Shirt: It is not only extremely soft to the touch but breathable as well. Our jersey is printed on sustainable fabrics so do not worry about shrinkage, never flake, peel, or crack. Machina washable, tumble dry on low heat, no bleach.
  • Material: 92% Polyester - 8% Spandex
  • Printing technique: dye-sublimation
Basketball Jersey Tank: It is not only extremely soft to the touch but breathable as well. Our jersey is printed on sustainable fabrics so do not worry about shrinkage, never flake, peel, or crack. Machina washable, tumble dry on low heat, no bleach.
  • Material: 90% polyester + 10% spandex.
  • Moisture-wicking properties.
  • Ensures durability, side seams a stylish classic fit.
  • Suitable for any sport activities, yoga session.
  • A good choice of gift for your loved one who like working out.
Basketball Suit: Our basketball suit is perfect for fans, featuring a lightweight construction with a V-neck collar, sleeveless design and flat lock seams that provides all day comfort. Players embraced the accessorized look more as an expression of personal style than anything else. Made of a lightweight polyester air-mesh, this basketball clothes set will keep you cool during the warmer months, just in time for playoff season. This suit was made with comfort in mind. Cut a bit slim to give you the most flattering fit possible.
  • Material: 100% Polyester
  • Printing technique: Digital Printing
Twill Cap:
  • Our hats are available in a variety of colors and are suitable for both men and women. They provide excellent sun protection and are ideal for any outdoor activity! With adjustable snap back construction (one size fits all), everyone in your family can now wear these hats!
  • Add style and personality to your hat collection with a custom printed classic cap.
  • Constructed with 100% premium polyester that’s lightweight for maximum comfort and breathability.
  • Universal Fit: One size fits most with an adjustable snapback closure.
  • Printing technique: Sublimation
Care:
  • Do not bleach
  • Do not wash

4 reviews for Official Shirtz Cool Merch The Idk I Don’t Know I Straight Up Know Nothing Tee Shirt

  1. Jamie McGuire Mason (verified owner) –

    I am very happy with my first, and recent, purchase. The top is constructed beautifully and the quality is much better than other basic t-shirt brands I’ve tried.

  2. Zane Angel (verified owner) –

    Really happy with the products I received. The quality of the fabric is excellent! Thick, soft, perfect. I really value the effort put behind being an ethical and sustainable company and this was the main reason for my purchase. Also, the customer service I received was great. Will definitely recommend your products to friends and family.

  3. Rowan Julian (verified owner) –

    I thought your service was excellent and the quality of the product seems excellent as well.

  4. VOYA Lucas (verified owner) –

    Liked the shirt. Thanks so much.

Only logged in customers who have purchased this product may leave a review.

  • Production Time: All orders are processed within 2 - 4 business days. Particularly for 3D and All Over Print shirts, production time can be up to 7 business days.
  • Processing Time: It takes 1 - 2 days to ship your order to our warehouse, put your name and address on it and ship out.
  • Delivery Time: Delivery time is equal to production time plus processing time and shipping time depending on the region, country and shipping package.
  • Shipping Cost: 
    • The Standard shipping price is $4.99 (4-8 business days).
    • The Ground shipping price is $10.99 (3-6 business days).
    • The Fastship shipping price is $19.00 (2-4 business days).
    • International shipping price is $14.99 (2-3 weeks).
    • Order 2 items or $64.99 for our FREE SHIPPING (USA Only)
    • Please Note: Estimated delivery time does not include production time 2-7 business days.
    • Business days: From Monday to Friday excluding holidays.
  • Return & Exchange: If for some reasons you are not happy with your purchase, we will happily work with you to correct the problems. Items can be return/exchange and get Refund within 30 days of delivery date.
  • Tracking Number: When available, we will send you the tracking number with the confirmation email so that you can track the package online.
  • If you have problems with shipping please send to email: [email protected]
Official Shirtz Cool Merch The Idk I Don't Know I Straight Up Know Nothing Tee Shirt
Official Shirtz Cool Merch The Idk I Don’t Know I Straight Up Know Nothing Tee Shirt
Original price was: $24.99.Current price is: $22.99.