Description
14x21 K3™ Professional 3D Frame Kit • 3-1/2" Deep • 3:2 Film • K3K-1421
Our Masterpiece® 3D™ K3 Professional 3-1/2" Deep Stretcher Bar Kit is the ultimate museum quality solid-wood stretcher system. It's so unique, it earned us a Patent! All you need to do is select the frame size and you will receive everything you need to build a museum class Stretcher Bar Frame. We have 6105 sizes available in this and two other depths. Get Any Size You Want!
Discover our Lost Sizes - a series of unique canvases in the celebrated 3:2 Film aspect ratios, including this 14x21 size. Created by Masterpiece®, these sizes are perfect for artists who desire something outside the norm.
True 3:2 Film Proportion - 14x21 Size
The 3:2 aspect ratio is a very familiar format film, computer screens, and video, and, of course, is an aesthetically appealing proportion for your artistic compositions. Most 35 mm film cameras are based on this exact proportion, so our brains are trained to see images in this same ratio. It is commonly used for landscape photography and artwork, as it allows for a wide, panoramic view of the scene. It can be used to create a sense of balance and harmony in the composition, providing depth and perspective, as the longer sides of the canvas allow for more space to depict the background or foreground elements of the scene.
Even though this proportion is widely used, there are only a handful of commonly available standard canvas sizes in this ratio. There are a whole collection of intriguing (what we call) Lost Sizes, which are uncommon sizes in this common proportion. Unusual canvas sizes add intrigue to your artwork and an additional story to tell about your painting.
Explore other sizes in this same 3:2 aspect ratio:
12x18 • 16x24 • 18x27 • 20x30 • 22x33 • 24x36 • 26x39 • 28x42 • 30x45 • 32x48 • 34x51 • 36x54 • 38x57 • 40x60 • 42x63 • 44x66 • 46x69 • 48x72 • 50x75 • 52x78 • 54x81 • 56x84 • 58x87 • 60x90 • 62x93 • 64x96 • 66x99 • 68x102 • 70x105 • 72x108 • 74x111 • 76x114 • 78x117 • 80x120
Explore other Masterpiece® products in this exact 14x21 size:

- Super strong 3D™ Pro K3™ Stretcher Bar is a very popular among contemporary artists whose painting will be displayed without a frame.
- For this 14x21 large size frame, the frame provides the ultimate foundation for your art with increased strength and stability
- Provides a 3.5" deep stretched canvas which makes a bold and commanding display
- 1-1/4" wide Stretcher Bars
- All Bars have an exclusive groove on the inside perimeter of the frame to which cross braces and Diamond Corner Braces attach
- Solid Ponderosa Pine or Fir from the Pacific Northwest

3D™ Pro 3.5 Stretcher Bar • 1/2" Canvas Clearance
1/2" Canvas Clearance is the space between the Bar and the canvas. Generally speaking, more clearance reduces the risk of the canvas touching the wood and creating unsightly lines during painting. Our design provides the optimal clearance so as not to impact your painting, but still leaving enough wood to the maximize strength of the Stretcher Bar.
- Produces a 3.5" deep stretched canvas (Actual depth is slightly thinner)
- 1.25" wide Stretcher Bar
- All Bars have an exclusive groove on the inside perimeter of the frame to which cross braces and Diamond Corner Braces attach
- Solid Ponderosa Pine or Fir from the Pacific Northwest

No Finger Joints!
Solid Wood is far superior to finger jointed wood, which is many small pieces glued together, each with varying grain densities that absorb and shed moisture at varying rates, expanding and contracting non-uniformly as environmental conditions change, and causing the wood to bow and the finger joints to eventually fail.
A single homogeneous kiln-dried solid wood Stretcher Bar outperforms and outlasts a finger jointed Bar whose sole purpose is to save the manufacturer cost, not contribute to the archival value of artwork intended to last a millennium. As a manufacturer, Masterpiece® does its part to conserve as much wood as possible, and still provide a quality product that will out-perform any other in the marketplace.

Sustainable Forests - A Precious Natural Resource
The air that we breathe depends upon our healthy forests the world over. For this reason, we only use lumber from the sustainable forests of the Pacific Northwest, so we can guarantee that our nation's precious natural timber resources are available for future generations.

24x31 is the Canvas Size Needed for this 14x21 Frame
Please note that you will need a canvas that is at least 10 Inches larger than the actual frame size to ensure proper stretching. This will provide ample material to stretch the canvas and attach it to the back of the frame. If you prefer to attach the canvas from the edge of the stretcher frame, you can reduce the size of your canvas by approximately 3/4" all the way around the frame. This will allow you to paint on the edge of the canvas and hang your artwork without needing a separate picture frame. And, if you ever need to remove the canvas from the frame and re-attach it, you'll have enough material to do that too.
Tight'n'Up™ Liquid Canvas Retensioner
One of our most appreciated products helps make your canvas tighter! Stretching a canvas tightly can be a challenge. Our Frame Kits include the Corner and Brace Keys that you will need to add tension, but Tight'n'Up™ Liquid Canvas Re-Tensioner is a way that you can use to add tension to the canvas without needed to use the keys. It canvas be sprayed on the back of a canvas to repair most canvas tension issues.
With Tight'n'Up™, you can add tension to just a small area, or a large area. Simply spray it lightly on the back and brush it into the canvas, and within seconds, your canvas becomes tighter and stays tighter. The more you use, the tighter it gets. Recommended for acrylic primed cotton or linen canvas. We do not recommend it for oil primed canvas because there are simply too many different types of oil primed canvas, but used conservatively at your own risk, it will tension any canvas.

Rooted in California and flourishing since 1965, Masterpiece® takes pride in its family-led legacy of crafting North America's premier Stretcher Bars. Our quest for excellence isn't just a goal but a commitment, positioning us as the trailblazers in the domain of fine-art canvas. Our innovative patents have set new benchmarks, ensuring our offerings stand unmatched. Dive into the tactile experience of our products, and you'll instantly recognize the distinct Masterpiece® quality, a signature appreciated by both your clientele and future art connoisseurs.

Beauty lies in the eye of the beholder.
♦ Plato
The ancient Greek philosopher, Plato, often explored the realms of form, ideas, and perception. At the heart of many of his dialogues was a quest for understanding the nature of beauty and truth. While deeply philosophical, this assertion of beauty's subjectivity has profound implications. Rather than offering a fixed definition, Plato's words give power to the observer, granting them the authority to define and recognize beauty in myriad forms.
This perspective liberates. It suggests that art isn't confined to a single interpretation or a universally accepted standard. Each piece we create holds the potential to connect, inspire, and evoke emotions in diverse ways, based on the viewer's personal experiences and perspectives. In understanding Plato's sentiment, we are reminded of the deeply personal relationship between the creator, the creation, and the observer. The magic of art is its ability to be ever-evolving, changing meaning and significance with each new pair of eyes that behold it.
Creativity is the heart of what we both do. So we've curated this empowering quote and some background. And, in our own act of creation, we provide this unique portrayal we made of Plato.
Additional Details
- SKU:
- K3K-1421
- Canvas and Depth:
- 3.50 In. Frame Kit
- Width:
- 14 Inch
- Length:
- 21 Inch