Last updated: · Written by Marcus Richardson, founder of Paint A Moment
In short
Framing a paint by numbers means one of two jobs: stretching the canvas over wooden bars and fitting a float frame, or flattening it into a frame bought in centimetres. Which one you need depends mostly on how big the canvas is, because only two common kit sizes, 30x40cm and 40x50cm, have an exact off-the-shelf match in the UK. Every other size needs a stretched canvas, a mount, or a made-to-measure frame.
Most paint by numbers canvases arrive rolled, which is why framing comes down to stretching or flattening. The hard part is sizing. Paint by numbers is a metric product and most of the UK frame market is not, so the frame you already own almost certainly will not close.
We checked our own range against what IKEA, Hobbycraft and the high street sell in October 2026. Of the eight sizes we make, two have an exact off-the-shelf match. The other six need stretching, a mount or a framer.
Which type of canvas do you actually have?
There are three formats and each frames differently. A rolled canvas is loose fabric with a blank border, so it needs stretching or mounting. A canvas already on stretcher bars only needs an outer frame if you want one.
At Paint A Moment every kit comes in one of three formats: No Frame (rolled), DIY Frame (the canvas plus a flat-packed pine frame you assemble), and Pre-Framed (already stretched and ready to paint, then ready to hang). There is no canvas board option. Pre-framed stops at 40x50cm on both our ready-made and personalised kits, because the supplier cannot stretch anything larger than that. From 50x60cm up, the DIY frame is the ready-made option.
The DIY frame is less work than it sounds. It is four pre-notched pine bars that push together by hand, around fifteen small pins, and two brass hanging brackets. No staple gun and no tools. The stretcher-bar route further down needs both.
A rolled canvas has a blank, unprinted border of a few centimetres on every side. That margin is not waste. It is what wraps around the bars, so never trim a rolled canvas flush to the painted edge before you have decided how you are framing it.
Which frame fits each paint by numbers size?
Match the canvas in centimetres and ignore inches and A-sizes entirely. The table below is our full size range against what is genuinely available in the UK, checked in October 2026.
| Canvas size | On which kit | Off-the-shelf match | What to do |
|---|---|---|---|
| 20x30cm | Both | Near miss: IKEA RÖDALM 21x30cm | 1cm too wide. Leave the mount in, or order pre-framed. |
| 30x40cm | Both | Exact: IKEA RÖDALM 30x40cm, about £7 | Take the supplied mount out and it fits perfectly. |
| 40x40cm | Personalised | None. Squares are rare on the high street | DIY frame, or a square float frame. |
| 40x50cm | Both | Exact: IKEA RÖDALM 40x50cm, about £10 | The easiest size to frame cheaply. Mount out. |
| 50x50cm | Personalised | None | DIY frame, or a square float frame. |
| 50x60cm | Both | Near miss: a 20x24 inch frame is 50.8 x 61cm | About 1cm oversized. Needs a mount, or go float. |
| 60x70cm | Ready-made | Near miss: a 24x28 inch frame is 61 x 71.1cm | Hard to find in the UK. Float frame is the sane route. |
| 60x80cm | Personalised | None. IKEA jumps 50x70cm to 61x91cm | Stretch and float frame, or made to measure. |
One change that catches people out: IKEA discontinued the RIBBA range most framing guides still recommend, and replaced it with RÖDALM. RÖDALM comes in 10x15, 13x18, 21x30, 30x40, 40x50, 50x70 and 61x91cm, with a 3cm deep profile and a removable mount. It is a flat frame, not a box, so it suits an unstretched canvas and will not take one that is already on bars.
Why do UK high-street frames often not fit?
Because the frame market is built around imperial photo sizes and A-series paper, and a paint by numbers canvas is neither. A frame 10mm out will not close, and one 10mm oversized leaves a gap you cannot unsee.
- A3 is 29.7 x 42cm. A 30x40cm painting is 3mm too wide for it and 2cm short of it.
- 16 x 20 inches is 40.6 x 50.8cm. That is 6mm and 8mm bigger than a 40x50cm canvas. Usable with a mount, poor without.
- A2 is 42 x 59.4cm. Nothing we make fits it.
- Squares are the worst served. 40x40cm and 50x50cm are common personalised sizes and almost nobody sells a matching frame.
So search in centimetres, and ignore anything sold as A3, A2 or "16 by 20". If your size is one of the eight without a match, the quickest fix is to choose the DIY frame when you order, which arrives cut to the canvas.
How do you stretch a rolled canvas onto stretcher bars?
Assemble four bars into a rectangle, lay the canvas face down with the bars centred on it, staple the middle of each side in turn, working outwards in opposite pairs and pulling the canvas taut, then fold the corners last. Allow about 30 minutes.
- Flatten the canvas first. Lay it face down under heavy books for 24 to 48 hours, or press the back with a warm iron through a tea towel. Never iron the painted side. Our guide to getting wrinkles out of a canvas covers the stubborn cases.
- Seal it before stretching. Stretching flexes the paint film, and unsealed acrylic on a folded corner can crack. Our guide to sealing a paint by numbers covers which varnish to use and how long to leave it.
- Build the frame. Stretcher bars have mitred, interlocking corners that tap together by hand. Check both diagonals measure the same before you staple anything, otherwise you lock in a skewed rectangle.
- Centre the canvas. Face down on a clean surface, bars on top, equal margin on all four sides. A 5mm error here shows badly on the finished piece.
- Staple the centres. One staple in the middle of the top bar, then the bottom, then left, then right, pulling firmly each time. Canvas pliers help on the larger sizes but are not essential.
- Work outwards. Add staples every 4cm to 5cm, always alternating opposite sides, stopping about 6cm short of each corner.
- Fold the corners. Pull the corner point straight in over the bar, then fold the two flaps flat against the side, one over the other. Staple through the fold on the back edge if you plan to leave the edges visible.
Tools: a staple gun with 6mm to 8mm staples, scissors and a tape measure. Expect roughly £10 to £20 for a basic staple gun, and roughly £10 to £20 for a set of four stretcher bars for a 40x50cm canvas from art suppliers such as Jackson's Art, Cowling & Wilcox or GreatArt. Prices vary by bar depth, so treat those as approximate.
Should you use a float frame instead?
A float frame, also called a tray frame, holds a stretched canvas with a small shadow gap around it so the canvas appears to hover inside the moulding. It is the best-looking option for a painted canvas, since no glass flattens the brushwork, and it is built to canvas sizes rather than photo sizes. That is why it answers six of our eight sizes.
The catch is cost and the fact that the canvas must already be on bars. Expect roughly £30 to £45 for a ready-made wooden tray frame for a 40x50cm canvas, and more for the larger and square sizes. Made-to-measure suppliers such as EasyFrame and Picture Frames Express cover anything the shelf does not.
They also solve a problem particular to this hobby. Acrylic has texture, and glass presses against it. If a piece took you 30 or 40 hours, and our guide on how long paint by numbers takes explains why the larger kits do, it deserves better than being squashed under glazing.
Where should you buy frames in the UK?
- IKEA. Cheapest by a distance for 30x40cm and 40x50cm, around £7 and £10 in black. Limited on finish, and no help at all for the other sizes.
- Hobbycraft. Stocks 30x40cm and 40x50cm in oak effect, black, white and grey, dearer than IKEA but you can see it before you buy.
- The Range. Good for larger poster frames and clip frames, stock varies by store.
- eBay and Amazon. Where to find stretcher bars, float frames and odd sizes. Read the listed measurements carefully, since many sellers convert imperial badly.
- A made-to-measure framer. The right call for squares, 50x60cm, 60x70cm and 60x80cm. Expect roughly £60 to £150 for a bespoke 40x50cm frame depending on moulding and glazing, and get two quotes.
How do you hang a finished paint by numbers?
Fit two D-rings about a third of the way down the back, one on each side, and hang from two picture hooks set level and roughly 20cm apart. Two fixings stop the piece tilting. Hang so the centre of the painting sits about 145cm from the floor, which is standard gallery eye level.
A framed 40x50cm canvas weighs well under 2kg, so a standard hardwall hook is enough in plaster. For plasterboard use a self-drive fixing rated to 5kg or more. Keep finished paintings out of direct sunlight, since acrylics fade over years of strong light, and off the wall directly above a radiator. For more ideas once it is up, see what to do with a finished paint by numbers.
If you are still choosing a kit and want something that frames easily, 30x40cm and 40x50cm are the two sizes you can frame for under a tenner, and they run through the best sellers and the easy kits. A personalised kit made from your own photo is the one most worth framing properly, and the custom kit page lets you add the DIY frame at any size.
Frequently asked questions
What size frame do I need for a 40x50cm paint by numbers?
A frame measured 40x50cm in centimetres, not a 16x20 inch frame, which is actually 40.6 x 50.8cm. IKEA RÖDALM 40x50cm is around £10 and fits exactly once you remove the supplied mount. Hobbycraft also stocks 40x50cm frames at a higher price.
What fits a 50x60cm or 60x70cm paint by numbers?
Nothing on the high street fits either exactly. IKEA jumps from 40x50cm to 50x70cm, and the nearest imperial frames, 20x24 inch and 24x28 inch, are both about 1cm oversized. Stretch the canvas and use a float frame, order a made-to-measure frame, or choose the DIY frame when you buy the kit.
Are IKEA RIBBA frames still available for paint by numbers?
No. IKEA discontinued RIBBA and replaced it with RÖDALM, which comes in 10x15, 13x18, 21x30, 30x40, 40x50, 50x70 and 61x91cm. Only 30x40cm and 40x50cm line up with a paint by numbers canvas. Many older framing guides still quote RIBBA sizes.
Should I varnish my paint by numbers before framing it?
Yes, seal it first. Varnish protects the paint from dust and handling, evens out the patchy sheen acrylics dry with, and reduces the risk of cracking when you fold the canvas over stretcher bars. Let it cure fully before you stretch or frame the piece.
Can I frame a paint by numbers without glass?
Yes, and for a painted canvas it usually looks better. Glass adds reflections and presses against the brush texture. A float frame holds a stretched canvas with no glazing at all. If you do use glass, choose a frame deep enough that the glazing never touches the paint.
New to the hobby? Start with our beginner's guide to paint by numbers, or browse kits designed specifically for adults.
