Custom video canvas size: why one off formats never get built
Quick Answer
A custom video canvas size is a frame dimension outside your standard set, built for a specific placement like digital out of home or an odd banner unit. Teams skip those placements because the canvas only gets built when the format recurs, and a genuine one off never clears that bar.
What is a custom video canvas size, and who asks for one?
A brand team wanted ultra wide video for a physical placement. Large screen, unusual ratio, the kind of thing that looks great in a planning deck. The request died in one sentence: we would have to create a custom export size for this. The reply was just as short. These are one offs.
That exchange is the entire economics of non standard video. The people who ask are almost never the creative team. They are the media people, working from a placement list that does not care what sizes you happen to own.
do you have that functionality for different ad sizes as well? So for our media team, if they're running digital out of home
That is a creative director at a global content delivery and cybersecurity company, on a call about scaling video. He is not asking whether the tool can render wide. He is asking whether his media team's placement list and his video system are the same shape.
Why do custom video canvas sizes get refused?
Building a canvas is a fixed cost, paid once, and it only pays back over how many times the format comes around again. Weekly formats amortize. A single stage screen at one conference does not.
So the refusal is rational, and it is also invisible. Nobody writes down "we declined out of home this year because of export sizes." The placement simply never appears in the plan, and the following year nobody remembers it was possible.
Buyers ask about this directly once they start planning real campaigns:
if we had a new size, let's say for paid media like a 300 by 250 and it isn't already in the list
An employer brand and paid media marketer at a customer engagement software platform, on an onboarding call. Her very next question was the one that matters more:
do you just have a list of all of the sizes you already have in this platform
The list is the product surface. What is on it gets made. What is off it becomes a favour someone has to ask for.
Which video formats justify a custom canvas size?
Sort placements by recurrence rather than by prestige and the answer stops being a judgement call.
| Placement | How often it recurs | Who asks for it | Does the canvas get built |
|---|---|---|---|
| Social vertical and square | Weekly | Social and content | Yes, already in the set |
| Standard banner units | Every campaign | Paid media | Usually, once the unit repeats |
| Digital out of home | A few times a year | Media and brand | Rarely |
| Event and stage screens | Once per event | Brand and events | Almost never |
| Ultra wide brand moments | One off | Brand | No |
Two rows down that table is where the interesting money sits. Out of home and stage screens are the placements with the most physical presence and the least tooling support, which is why they keep getting quietly dropped.
What happens when you resize instead of building the canvas?
The usual workaround is to take the widescreen master and squeeze it. That works until the composition stops surviving the crop.
when you want to change the ratio for example, to a square or to a vertical, it gets cut
A social media content marketer at an enterprise open source software company, describing what happens at export time. Her problem is not the ratio. It is that the layout was never told what to do at that ratio, so the frame edge decides for her.
This is why treating aspect ratio as a brand rule rather than an export setting changes the outcome. A rule can be authored once and applied by the system. A crop is a guess made after the fact.
How do media teams get non standard video sizes without a bespoke build?
Make size a parameter of the motion system instead of a property of the file. When the layout knows how it wants to behave at an unfamiliar width, a new size is a request rather than a project, and the recurrence test stops being the gate on whether a placement is possible.
That is the difference between owning five sizes and owning a system that answers for any size. Capsule customers produce 10x more videos than they did before, and most of that volume is the same creative meeting more placements rather than more shoots.
For teams running video for paid media placements, the practical step is to write the placement list first and the size list second. Our notes on managing paid media video specs cover how to keep that list from rotting.
FAQ
What is a custom video canvas size?
A frame dimension outside your standard export set, created for a specific placement. Digital out of home boards, stage screens and unusual banner units are the common cases.
Why will nobody build a custom video size for a one off placement?
Because the build cost is paid once and recovered over repeat use. A format that appears a single time has nothing to recover it against, so the placement gets dropped instead.
Can you just resize an existing video to a new aspect ratio?
Sometimes. The composition has to survive the crop, and layouts authored for widescreen frequently do not. Responsive behaviour has to be defined in the template rather than decided at export.
Who inside an enterprise usually asks for a non standard video size?
Media and paid teams, working from a placement list. They are asking whether your size list matches their buy, which is a different question from whether your tool can render wide.