Underwear set + swimsuit pattern for boys 

Underwear : tank-top and shorty and a swimsuit boxershorty
Underwear : Ribbing at armholes and neckline, fancy elastic at waistband, gusset at shorty front with full lining and enclosed seams, and dart at gusset. No seam at back, side seams.

Swimsuit : seams at crotches, no side seams, elastic into waistband, full lining 
 

Sewing level :   easy to intermediate

What you will learn with this sewing pattern:

 how to sew ribbing, how to assemble a gusset with lining and enclosed seams, how to sew elastics, how to assemble a full lining at swimsuit.

Age range :   3, 4, 5, 6, 7, 8, 9 10, 11, 12 years

See the size guide

Specificities regarding underwear and swimwear

Underwear and swimwear must be very close to the body (for swimsuit, panties or boxers in particular because they are small parts for which the height is less important than the build and the age of the child ....) it is recommended not to take an age above the real age of the child. For example, as long as a child has not reached 7 years, make small pieces of swimwear and underwear in 6 years. If in doubt, it is better to take the size below than the size above.

Material suggestions: 

Underwear : jersey with or without elastan, ribbing.  
Swimsuit : jersey in polyamide or polyester with lycra (around 20% of lycra). For the lining : use main fabric or special polyester moss crepe

Trims : 

• basic or fancy elastic 3 to 4 cm wide for underwear short
• elastic 2 cm wide for the swimwear shorty
• fully voluminous polyester thread (multi-fibers) and polyester basic thread
• special needle for jersey and evene microtex needle for swimsuit is better
• double needle for hems (if you do not have one, it is possible to replace all the points made with a double needle by a zig-zag stitch) - prefer the special needle for jersey 
• Wonder clips (better than pins for the swimsuit fabric)
• double training foot for sewing machine