Which thread to start with for machine quilting
- For piecing, Aurifil says its 50wt thread is thinner than its 40wt and gives flatter, more accurate seams.[1]
- For quilting, Simply Quilting calls 50wt the most popular thread weight in quilting and recommends Aurifil 50wt for it.[2]
- For more visible quilting, Aurifil 40wt gives greater stitch definition, and Aurifil 28wt is described for machine quilting as bold, with Simply Quilting also saying 28wt increases stitch definition.[1][2]
- For polyester, WonderFil describes Master Quilter 40wt as a cottonized polyester with a matte finish and no stretch.[4]
- For a polyester strength with a cotton look, WonderFil describes Ultima 40wt as a polyester core wrapped in cotton.[4]
- Choose the piecing thread first, then the quilting thread for how visible you want the stitching, and pick the fibre last.
How to read thread weight labels
In the wt system a higher number means a finer thread, so Aurifil 50wt is finer than Aurifil 40wt. Aurifil measures its weight as Ne, the number of 840-yard hanks that weigh one pound, so Aurifil 50wt is 50 hanks, or 42,000 yards, to the pound.[1][5]
Tex works the other way: a higher tex number means a heavier thread. Juki Junkies gives the example that TEX 70 is heavier than TEX 45, while a 60wt is finer than a 40wt. Echidna Sewing describes tex as the weight in grams of 1,000 metres of thread and as a consistent international standard for textiles.[3][5]
Denier is a traditional system for continuous filament threads such as silk, nylon and polyester. Echidna Sewing describes it as the weight in grams of 9,000 metres, and notes that a label such as 120D/2 combines two plies, giving a total of 240D.[3]
The wt system is the most common one for home sewing and quilting in North America, but Echidna Sewing calls it notoriously unregulated and says one brand's 40wt is often another brand's 35wt.[3]
Compare labels only within one brand's chart, and check the maker's specification before you switch brands in the middle of a quilt.
Cotton, polyester and specialty fibres compared
| Attribute | Cotton | Polyester | Cotton-wrapped polyester | Rayon | Monofilament |
|---|---|---|---|---|---|
| Lint[4] | Konfetti and Tutti 50wt are double gassed for a low lint finish (WonderFil) | Master Quilter 40wt is described as completely lint-free (WonderFil) | Ultima 40wt is described as the cleanest wrapped quilting thread on the market (WonderFil) | No lint claim made for this fibre | No lint claim made for this fibre |
| Stitch visibility[1][4] | Aurifil 50wt sinks into the fabric for subtle definition, and Aurifil 40wt gives greater definition (Aurifil) | Master Quilter 40wt has a matte finish; no visibility claim made (WonderFil) | Ultima 40wt has a cotton look on the outside (WonderFil) | Accent 12wt and GlaMore 12wt suit outlining and decorative quilting (WonderFil) | Still shows under bright lights (WonderFil) |
| Feel with dense stitching[4] | WonderFil says dense quilting with 40 or 50wt thread can make fabric stiff | Master Quilter 40wt has no stretch (WonderFil) | No stiffness claim made for this fibre | No stiffness claim made for this fibre | Can make quilts feel stiff and inflexible with dense stitching (WonderFil) |
| Sheen or sparkle[1][4] | Aurifil cotton is mercerized, which gives it a sheen (Aurifil) | No sheen claim made for this fibre | No sheen claim made for this fibre | Dazzle 8wt is glossy rayon with a metallic strand; GlaMore 12wt has a metallic strand (WonderFil) | No sheen claim made for this fibre |
| Strength and durability[1][4] | Aurifil says mercerizing also strengthens the thread (Aurifil) | No durability claim made for this fibre | Gives the strength and ease of polyester with a cotton look (WonderFil) | Not sturdy enough for edge to edge quilting on quilts in use (WonderFil) | No durability claim made for this fibre |
| Typical use[2][4] | Piecing and quilting; Simply Quilting calls 50wt the most popular quilting weight | Recommended by WonderFil for those new to longarm quilting | Polyester stitching with a cotton look (WonderFil) | Outlining, decorative quilting in small patches, art and wall quilts (WonderFil) | Many quilters use it when quilting should not show (WonderFil) |
Matching thread weight to your quilting style
- Choose the piecing thread first. Aurifil says its 50wt is thinner than its 40wt and gives flat seams, and Cabin Quilters, a quilting blog, says most quilt professionals recommend an all-cotton thread for piecing.[1][6]
- Pick the quilting weight by how visible the stitching should be. Aurifil describes 80wt for superfine detail, 50wt for a subtle effect, 40wt for greater stitch definition and 28wt by machine for bold results.[1]
- If the quilting should disappear, WonderFil suggests a finer thread such as InvisaFil for dense or micro quilting, because it takes up little extra space in the fabric.[4]
- Check the bobbin against the maker's chart. Simply Quilting advises 50wt in the bobbin with Aurifil 50wt; for other weights, follow the thread maker's own chart.[2]
- Test the combination on a small spool and through the same layers you will quilt before starting a large project. Cabin Quilters advises starting with a small spool, and Juki Junkies advises testing on your actual project layers.[5][6]
Needle pairing for each thread weight
- Aurifil 50wt: 80/12 Microtex/Sharp, Universal or Denim needle; 4.0 longarm needle (Aurifil).[1]
- Aurifil 40wt: 80/12 Microtex/Sharp, Universal or Denim needle; 4.5 longarm needle (Aurifil).[1]
- Aurifil 28wt: 90/14 Topstitch, Quilting or Denim needle; 4.5 or 4.0 longarm needle (Aurifil).[1]
- Aurifil 12wt: 100/16 or 90/14 Topstitch needle; 4.5 longarm needle (Aurifil).[1]
- Aurifil 80wt: 70/10 or 80/12 Microtex/Sharp needle, or an embroidery needle (Aurifil).[1]
- Aurifil monofilament: 80/12 or 70/10 Topstitching or Microtex/Sharp needle (Aurifil).[1]
- Polyester in Aurifil's chart: 80/12 Microtex/Sharp, Universal or Denim needle; 3.5 or 4.0 longarm needle (Aurifil).[1]
- Needle advice differs between makers and applies to their own products, so check the chart for your brand and weight.
Mistakes that cause lint, breakage and poor stitches
Bargain cotton thread can create a lot of lint, which gathers in the moving parts of a machine. Cabin Quilters, a quilting blog, advises avoiding bargain threads because they are not usually durable in the finished quilt.[6]
WonderFil says glue or residues that some threads carry to look low lint can gum up a machine and be harder to clean out than ordinary lint.[4]
Buying a large size of an untested thread is a common mistake. Cabin Quilters reports that a new thread can wreak havoc in a machine, break often or not look right, which is why it suggests starting with a small spool.[6]
Two threads with the same weight number are not guaranteed to match. Echidna Sewing notes that one brand's 40wt is often another brand's 35wt, so compare each product's own specifications.[3]
Aurifil 80wt is very delicate. Aurifil recommends a very thin, very sharp needle, slow sewing and lengths of 14 to 16 inches for minimal breakage.[1]
Monofilament still shows under bright lights and can make quilts stiff when stitching is dense, according to WonderFil.[4]
Questions readers ask about quilting thread
Should the bobbin use the same thread as the top?
Not always. Simply Quilting advises 50wt in the bobbin with Aurifil 50wt; for other weights and brands, follow the thread maker's own chart for the exact product you are using.[2]
Is cotton or polyester better for beginners?
Simply Quilting calls 50wt cotton the most popular quilting weight, favoured by beginners and experts, while WonderFil recommends Master Quilter 40wt polyester to anyone new to longarm quilting. That polyester advice is for longarm work, so for a domestic machine, start with the cotton weights in the piecing section.[2][4]
What we could not confirm
- Weight labels are not regulated across brands, and the available material gives no universal conversion between brands' 40wt, 50wt or other numbers.
- Needle and bobbin pairings come from individual thread makers and apply to their own products, not to threads in general.
- Most fibre comparisons come from thread makers and sellers rather than independent tests on domestic machines.
- Polyester guidance is mainly for longarm quilting, so advice on polyester for a domestic machine is not covered.
- Rayon threads are described as unsuitable for edge to edge quilting on quilts in use, and no suitable alternative for that job is given.
Sources
- Aurifil Thread FAQ – Aurifil — checked 2026-10-27
- Your essential guide to the best quilting threads! | Simply Quilting — checked 2026-10-27
- A Home Sewer's Guide to Demystifying Thread Weights — checked 2026-10-27
- A Guide to Choosing the Best Quilting Thread - WonderFil Specialty Threads USA — checked 2026-10-27
- Thread Guide: TEX vs. Thread Weight — checked 2026-10-27
- Cabin Quilters — checked 2026-10-27